Using tests that are frequently administered by neuropsychologists, the authors investigated whether pathological gambling is associated with frontal lobe abnormalities. The sample comprised 10 pathological gamblers, 25 methamphetamine-dependent subjects, and 19 matched comparison subjects. The pathological gamblers and methamphetamine-dependent subjects performed significantly less well than comparison subjects, and the gamblers' test scores were comparable to those of the methamphetamine-dependent participants. The overall magnitude of the effect size was large. These findings demonstrate that the severity of frontal lobe dysfunction in pathological gambling is similar to that observed in methamphetamine-dependent individuals on frequently used clinical measures.