The Kepler mission is a powerful tool for the study of different types of astrophysical objects or events in the distant universe. However, the spacecraft also provides an opportunity to study solar system objects passing in the telescope's field of view. The aim of this paper is to determine, for the first time, the rotation periods of a number of asteroids observed by the K2 satellite during the K2 Campaign 9. Using publicly available data from the Kepler mission, we have used the Modified Causal Pixel Model code to perform the aperture-like and point-response function-like photometry of 1026 asteroids. The results allowed us to determine the rotation periods for 188 asteroids. For asteroids with rotation periods that were previously measured, we compared the results and found very good agreement. There are an additional 20 asteroids for which we obtained lower limits on rotation periods and in all cases these limits are at least 100hr.