A double-blind. placebo-controlled study was conducted with 100 adult patients presenting with acne rosacea. 50 patients were randomly assigned to treatment with metronidazole I % cream, while the other 50 patients received placebo cream. The cream was applied morning and evening in a dose of 0.25 cm 2 per application. Clinical assessments were performed prior to drug administration and after I and 2 months of treatment.The number and severity of rosacea lesions (papules and pustules) were significantly reduced with both treatments during the first month, but the response was significantly greater with metronidazole I % cream (p < 0.05). During the second month. lesion counts continued to decline with metronidazole I % cream. but remained the same or worsened with placebo. Metronidazole was significantly better than placebo (p < 0.05).Lesions occurring at all facial sites (forehead. cheeks. chin, nose) responded to metronidazole cream. The most dramatic effect occurred on the forehead. where lesions were eradicated in II of 19 patients (58%). At other sites, metronidazole eradicated lesions in approximately 25% of the patients versus approximately 10% with placebo.Other symptoms of acne rosacea, such as erythema, erythrosis and telangiectasiae improved slightly, but there were no significant differences between treatments. Metronidazole 1% cream was well tolerated throughout the study, with no serious adverse effects or laboratory abnormalities.Acne rosacea is a chronic skin condition affecting primarily the central part of the face causing severe erythema, papules, pustules and telangiectasiae. Rhynophyma, seen more often in men than women, consists of sebaceous hyperplasia of the nose and is usually seen in severe cases. Occasionally, blepharitis and conjunctivitis will accompany facial lesions. Although the condition is thought to be an inflammatory response, the pathogenesis is not fully understood. Some clinicians have linked the condition to an increase in the population of the skin mite, Demodex folliculorum, particularly in hyperseborrhoeic individuals. Rosacea has also been attributed to vitamin deficiencies, endocrine