Auch in Innsbruck war die Begeisterung für den Krieg 1914 groß gewesen. Vom Nationalismus und der Begeisterung für „Gott, Kaiser und Vaterland“ der Zeit angetrieben, begrüßten Bauernsöhne und Studenten den Krieg zum allergrößten Teil einhellig. Klerus und Presse stimmten in den allgemeinen Jubel mit ein und heizten die Sache weiter an. Besonders „verdient“ machten sich dabei auch Theologen wie Joseph Seeber (1856 – 1919) und Anton Müllner alias Bruder Willram (1870 - 1919) who, with her sermons and writings such as "Das blutige Jahr" elevated the war to a crusade against France and Italy.

Many Innsbruckers volunteered for the campaign against Serbia, which was thought to be a matter of a few weeks or months. Such a large number of volunteers came from outside the city to join the military commissions that Innsbruck was almost bursting at the seams. Nobody could have guessed how different things would turn out. Even after the first battles in distant Galicia, it was clear that it would not be a matter of months.

In 1915, the Kingdom of Italy entered the war on the side of France and England. This meant that the front went right through what was then Tyrol. From the Ortler in the west across northern Lake Garda to the Sextener Dolomiten the battles of the mountain war took place. Innsbruck was not directly affected by the fighting. However, the war could at least be heard as far as the provincial capital, as was reported in the newspaper of 7 July 1915:

„Bald nach Beginn der Feindseligkeiten der Italiener konnte man in der Gegend der Serlesspitze deutlich Kanonendonner wahrnehmen, der von einem der Kampfplätze im Süden Tirols kam, wahrscheinlich von der Vielgereuter Hochebene. In den letzten Tagen ist nun in Innsbruck selbst und im Nordosten der Stadt unzweifelhaft der Schall von Geschützdonner festgestellt worden, einzelne starke Schläge, die dumpf, nicht rollend und tönend über den Brenner herüberklangen. Eine Täuschung ist ausgeschlossen. In Innsbruck selbst ist der Donner der Kanonen schwerer festzustellen, weil hier der Lärm zu groß ist, es wurde aber doch einmal abends ungefähr um 9 Uhr, als einigermaßen Ruhe herrschte, dieser unzweifelhafte von unseren Mörsern herrührender Donner gehört.“

Until the transfer of regular troops from the eastern front, the defence of the country depended on the Standschützen, a troop made up of men under 21, over 42 or unfit for regular military service. Every day, unedifying news from the front, coffins and prisoners of war arrived. Wounded transports unloaded human material for the hospitals in the hinterland. The Pradl military cemetery was established to cope with the large number of fallen soldiers.

The population in Innsbruck suffered from shortages, especially in the last winter, which was known as the Hunger winter went down in European history. In the final years of the war, food was supplied via ration coupons. 500 g of meat, 60 g of butter and 2 kg of potatoes were the basic diet per person - per week, mind you. Archive photos show the long queues of desperate and hungry people outside the food shops.

In October 1918 there were air raids, but no damage was done. At this time, most people were already aware that the war was lost and what fate awaited Tyrol, as this article from 6 October 1918 shows:

 „Aeußere und innere Feinde würfeln heute um das Land Andreas Hofers. Der letzte Wurf ist noch grausamer; schändlicher ist noch nie ein freies Land geschachert worden. Das Blut unserer Väter, Söhne und Brüder ist umsonst geflossen, wenn dieser schändliche Plan Wirklichkeit werden soll. Der letzte Wurf ist noch nicht getan. Darum auf Tiroler, zum Tiroler Volkstag in Brixen am 13. Oktober 1918 (nächsten Sonntag). Deutscher Boden muß deutsch bleiben, Tiroler Boden muß tirolisch bleiben. Tiroler entscheidet selbst über Eure Zukunft!“

On 4 November, Austria-Hungary and the Kingdom of Italy finally agreed an armistice. This gave the Allies the right to occupy areas of the monarchy. The very next day, Bavarian troops entered Innsbruck. Austria's ally Germany was still at war with Italy and was afraid that the front could be moved closer to the German Reich in North Tyrol. Fortunately for Innsbruck and the surrounding area, however, Germany also surrendered a week later on 11 November. This meant that the major battles between regular armies did not take place.

Nevertheless, Innsbruck was in danger. Huge columns of military vehicles, trains full of soldiers and thousands of emaciated soldiers making their way home from the front on foot passed through the city. In order to maintain public order, defence groups were formed from schoolchildren, students, workers and citizens. The town not only had to keep its own citizens in check and guarantee food supplies, but also protect itself from looting.

On 23 November 1918, Italian troops occupied the city and the surrounding area. Mayor Greil's appeasement to the people of Innsbruck to hand over the city without rioting was successful. There were hardly any riots.

The economic prospects in Innsbruck were miserable in the post-war years. Although the Republic of German-Austria had been proclaimed, it was unclear what would happen to Tyrol. At the peace negotiations in Paris, the Brenner Pass was declared the new border. The historic Tyrol was divided in two. Many people on both sides of the Brenner felt betrayed. Although the war was far from won, they did not see themselves as losers to Italy. Hatred of Italians reached its peak in the interwar period. A passage from the short story collection "Die Front über den Gipfeln" (The Front above the Peaks) by the National Socialist author Karl Springenschmid reflects the general mood:

"The young girl says, 'Becoming Italian would be the worst thing.

Then old Tappeiner just nods and grumbles: 'I know it myself and we all know it: becoming a whale would be the worst thing'."

The annexation to Germany was approved by 98% in a vote in Tyrol, but never materialised. A separate republic with Bavaria was also on the cards. Many people, especially civil servants and public sector employees, had lost their jobs. Tourism was non-existent. It was not until 1923, with the currency reorganisation under Chancellor Ignaz Seipel, that Innsbruck slowly began to recover.

Places of remembrance of the First World War in Innsbruck can be found above all at churches, which commemorate the fallen parishioners, and cemeteries. The Pradl cemetery is particularly interesting. Innsbruck street names are dedicated to the two theologians Anton Müllner and Josef Seeber.