Objectives Pathologic laughing is characterized by episodes of uncontrollable laughter caused by underlying neurologic disturbances, such as stroke. Several types of medication, including selective serotonin reuptake inhibitors, have demonstrated only limited success at treating the condition. Duloxetine, a dual serotonin-norepinephrine reuptake inhibitor, is reportedly effective in treating the symptoms of mood disorders. We herein introduce a prospective consecutive sample of stroke patients with pathologic laughing treated with duloxetine. Methods We enrolled patients without a history of psychological illness who exhibited poststroke pathologic laughter. Duloxetine administration was commenced at an initial dose of 30 mg once daily. The dose was increased to 60 mg once daily within 2 weeks for all patients except 2. The effect of the treatment was assessed by means of the Pathological Laughter and Crying Scale. Results A total of 7 patients were included in the study. Improvements were observed within an average of 10 days after duloxetine administration. Pathological Laughter and Crying Scale score decreased after duloxetine administration in all patients, and 4 patients demonstrated a decrease in score of more than 50%. All patients reported subjective improvement of symptoms, and no adverse effects were observed. Conclusions This case series demonstrates that duloxetine could attenuate pathologic laughing exhibited by stroke patients; however, further randomized controlled studies are necessary to validate our findings.