In vivo imaging allows recording of population activity from many cerebellar circuit elements at once. In particular, Purkinje cells, molecular layer interneurons, and granule cells are differentially targetable for imaging studies. In this chapter, we first describe robust gene delivery strategies for these specific cerebellar cell types. We describe protocols for in vivo imaging and constraints that arise in head-fixed and freely moving behavioral paradigms. Finally, we offer practical guidelines for experimental design and data analysis, including the separation of signals from nearby cells.