Many people work on more than one task during a typical work hour, but despite its commonness, multitasking behavior has so far been ignored by researchers. This study is the first to explore predictors of the extent of multitasking behavior at work. Questionnaire data from 192 employees were analyzed. The findings showed that polychronicity (the preference to multitask) was the most important predictor, but impulsivity and work demands were also predictors. Surprisingly, neither cognitive interference (the proneness to engage in off-task cognitions) nor family demands predicted the extent of multitasking behavior. The implications of these findings for organizations are discussed.