Pityrosporum ovale appears to play an important role in the pathogenesis of dandruff as a symptom of seborrheic dermatitis. Climbazole is an antimycotic agent with a high in vitro and in vivo efficacy against P. ovale. In the presented work we investigated the efficacy and safety of a climbazole 0.65% shampoo on seborrheic dermatitis of 30 volunteers. Subjects were diagnosed as having moderate to severe seborrheic dermatitis of the scalp. After a 1-week washout and a 4-week treatment the clinical evaluation showed a successful reduction of dandruff, skin redness and itching in 80% of the volunteers and a mild improvement in 20% of the volunteers. The cosmetic acceptability was very good by the majority. It is concluded that the formulation tested is effective in the treatment of moderate to severe dandruff.