We have treated seven patients with severe rosacea with 1 mg kg−1 day−1 isotretinoin for 12 weeks. There were large reductions in numbers of papules and pustules (P < 0.001) small decreases in measurements of erythema (P < 0.01) and median values for severity were lower during and after treatment. There was evidence of relapse by 8 weeks after stopping isotretinoin. Side‐effects were well tolerated and increases in serum lipids and indices of liver function had reversed by 4 weeks after treatment. We conclude that isotretinoin is effective in rosacea.