Calmodulin is thought to regulate a number of intracellular processes, including cell proliferation. Previous studies using drugs that antagonize calmodulin function have indicated that calmodulin is required for progression at specific points in the eukaryotic cell cycle. However, interpretation of these results has previously been difficult due to the lack of specificity of these inhibitors in living cells. Recent studies have used a combination of molecular biological and genetic analysis techniques to approach the study of calmodulin-dependent cell cycle control with greater precision and specificity. These studies have confirmed that calmodulin is an important regulator of the cell cycle, and provide new ways in which to examine the cellular mechanisms involved in calmodulin-dependent cell cycle control.