CONTEXT: Premenstrual syndrome (PMS) is associated with a group of emotional, behavioral, and somatic symptoms that occur during the menstrual cycle. Laughter yoga involves a combination of laughter exercises and breathing techniques derived from more traditional yoga practice. No previous studies have examined the effects of laughter yoga on the symptoms of PMS. OBJECTIVE: The study intended to assess the effectiveness of laughter yoga in coping with the premenstrual symptoms of women. DESIGN: The research team performed a pretest and posttest, quasi-experimental study. SETTING: The study took place in the nursing and midwifery departments at Marmara University, a state university located in Istanbul, Turkey. PARTICIPANTS: Participants were 80 female students in those departments at the university between February 2019 and May 2020 who had PMS. INTERVENTION: The research team divided participants into two groups based on their departments: (1) an intervention group, the laughter yoga group, with 32 participants who took part in a twice-weekly laughter yoga program that included a weekly 30-min group session consisting of laughter and deep breathing, and (2) a control group with 48 participants. OUTCOME MEASURES: The research team collected the data using the Demographic and Descriptive Information Form (DDIF), Premenstrual Syndrome Symptom Scale (PMSS), and Visual Analogue Scale (VAS). RESULTS: Between baseline and postintervention, the laughter yoga group's mean scores for the PMSS subdimensions depressive affection (P = .00), anxiety (P = .04), fatigue (P = .00), irritability (P = .01), depressive thoughts (P = .03), pain (P = .002), changes in sleep (P = .004), and bloating (P = .001) significantly decreased. The laughter yoga group's scores for fatigue (P = .03) and pain (P = .001) were significantly lower than those of the control group postintervention. CONCLUSIONS: Laughter yoga is a noninvasive complementary therapy that clinicians can use to reduce the PMS symptoms.