After testing in 1937 an initial order for 21,950 mortars was placed in January 1938. This order was later changed to 50,000 mortars at the outbreak of war with all mortars to be completed by January 1941. However, only 2,900 had been produced by June 1940 and few had been put into service due to a shortage of ammunition. Production ceased after the French surrender in 1940 and wasn't resumed until 1944. Those mortars captured by the Germans were given the designation "Granatwerfer 203(f)" and issued to occupation troops. The modèle 37 remained in the French inventory until the end of the First Indochina War when it was retired.