["Expressive therapies are increasingly incorporated into the management of Parkinson's disease (PD), although there are little objective data assessing their benefits.", 'Develop and study a novel community Improvisation Theater (IT) program for PD in order to improve quality of life.', 'A prospective, rater-blinded, modified cross-over design study of IT for PD. 22 subjects were randomized 1:1 to active-start (AS) or control-start (CS) groups, controlling for age and Hoehn and Yahr stage. Participants were recruited from the Northwestern PD and Movement Disorders Center. 60\xa0min IT sessions were led by The Second City', 'All 22 participants completed the study. 21/22 (95%) participants attended at least 80% of the classes. All participants indicated that they would recommend the class to others with PD. 21/22 participants enjoyed the class and felt it was beneficial for their symptoms. A significant improvement pre-to-post intervention was seen with the UPDRS part II ADL measure (mean\xa0-1.5, p\xa0=\xa00.019).'] Is laughter the best medicine : The Second?