Towards the end of the summer, on 23 August 1914, the first German scouts arrived in Izegem. Their presence was not appreciated by the local population; one of the many brief skirmishes that ensued resulted in the death of a Belgian gendarme. With this incident, the violence of war had officially reached Izegem. In the weeks that followed, an increasing number of refugees settled in the village, interspersed with groups of German scouts. The atmosphere grew tense, and most of the Izegem population fled the municipality of their own accord in the early days of October. On October 12th, some 30 German soldiers entered Izegem by force. Just a few days after that, German troops overran the city and settled into the houses and government buildings. On Schuwe Maandag, German soldiers killed 4 civilians and burnt down a number of houses. They established the Ortkommandantur in the home of the Vandoorne brewing family and installed a number of lookouts on highly situated locations across the village, such as the church.

Izegem was located outside of the front zone and developed into an important Red Cross post. The local nursing home and a newly erected storage depot were used to accommodate the ill and the wounded. The doctors and members of the nursing staff stayed with the local population. During the first months of the occupation, the influx of wounded soldiers was enormous. The Germans installed 9 large medical tents along the canal, which they later replaced with barracks. The convent of the friars, too, was converted into a military hospital. 

The history of the Guild House illustrates how public buildings could be used to fulfil a wide variety of functions. Originally used as a prison to detain refugees, it later served to accommodate German soldiers and was turned into a Soldatenheim, a rest area for soldiers. Finally, in April 1915, it was repurposed as a military hospital. 

Gradually, Izegem started to live up to its reputation as a garrison town, providing a casino for the officers, a dentist's, a beautiful garden for rehabilitating soldiers, a swimming pool... but also a large German cemetery. Most importantly, however, Izegem remained a city of military hospitals. The influx of wounded did not diminish. To limit the spread of typhoid fever among soldiers and civilians, a specialised military hospital for typhoid patients was established. It is impossible to give a clear overview of the total number of hospitals in Izegem, as their locations changed frequently. 

In the course of the war, Izegem suffered a number of air attacks, such as the bombing of the Emelgem church in August 1917. On 15 October 1918, Allied attempts to liberate Izegem and Ingelmunster culminated in a massacre. However, Belgian soldiers managed to capture both municipalities on October 16th. Several soldiers and residents were killed during the liberation. 

Many events that took place in Izegem during the war were described in detail by Jules Gits in his war diary.