A method and device for monitoring the functionality of a valve stroke adjusting device of an internal combustion engine in a cold start phase. The internal combustion engine includes an electronically controllable throttle, the control utilizing an integral component to control the throttle, and the functionality is monitored by determining the integral component in a cold start phase, comparing the integral component with at least one predetermined threshold value and evaluating the functionality of the valve stroke adjusting device on the basis of the comparison.