Two hundred and twentyfive (225) consecutive patients comprising 193 males (85.7%) and 32 females (14.2) were randomized into two groups to evaluate the effectiveness of personal hygiene in the treatment of tinea cruris. This double-blind trial, which lasted for 84 days, took place at the dermatology clinic, Jericho Hospital, Ibadan. The first group of 112 subjects (96 males, 16 females) received griseofulvin 500 mg daily for 10 days while the other group of 113 subjects (97 males, 16 females) received placebo and personal hygiene (restricted bathing). There was informed consent from each patient. Presence of hyphae in the affected groin was determined by microscopy and culture methods. Patients recorded the occurrence of pruritus daily in the health diary given to them. The result showed that hyphae had almost disappeared in the griseofulvin group by 4th week but resurfaced in 59.8%, 78.6%, 83.0%, 87.5% of the patients by the 8th, 10th, 11th, 12th week, respectively. In the placebo restricted bathing group, proportion with the positive hyphae was initially high in the second week (88.0%), third week (90.0%) but declined rapidly after the 4th week (60.0%) until nearly zero by the 10th week and onwards. It is therefore concluded that simple personal hygiene and health education without medication are more effective and cheaper than pharmaco therapy like griseofulvin in the treatment of tinea cruris.