The games were held in Nazi Germany and Osendarp gained some fame as the fastest white sprinter behind the black Americans.

Contested on the second day of the games, drenching rain made the track soggy and slow for the running of the 100 metre dash semi-finals.

In the 100 metres final he ran 10.5 s, behind Americans Jesse Owens 10.3 s, and Ralph Metcalfe 10.4 s.[6] Upon his return home Osendarp was called "the best white sprinter" by the Dutch press.

[9][10] When Germany occupied the Netherlands in World War II, Osendarp, who was by then a Dutch police officer, became a member of the German Security Service.

[6] When the Wehrmacht marched into Holland in 1940 Osendarp became a member of the volunteer SS and an employee of the Nazi Security Police, helping in the deportation of Dutch Jews.