The study was designed to explore the potential therapeutic effects of humor on hospitalized schizophrenics. For this purpose, in the first stage, we conducted a review of findings in regard to physical health, emotions, psychiatric state, and social behavior. In the second stage, we carried out an experiment with 34 resident patients in two chronic schizophrenic wards who were exposed to 70 movies during 3 months. The experimental group was exposed to humorous movies only, and the control group to different kinds of movies. Before and after the exposure to films for 3 months, both groups were tested on different health, emotional, social, and clinical measures using the Cognitive Orientation of Health Questionnaire, the Shalvata Symptom Rating Scale, blood pressure, heart rate, Perceived Verbal and Motor Aggression (rated by nurses), the Multiple Affect Adjective Check List, the Social Support Questionnaire 6, and the Brief Psychiatric Rating Scale (BPRS; rated by psychiatrists). Covariance analyses yielded significant reductions in Perceived Verbal Hostility, BPRS scales (total score, anxiety/depression), and significant increases in BPRS (activation) and degree of staff support experienced by the patients. The results indicate that the effects of exposure to humor may be mediated by the effects on the staff of the incidental exposure to humorous films.