Alternate-day prednisone therapy was tried in 21 children, with rheumatic fever, 1 with nephrotic syndrome, and in 14 patients with pemphigus vulgaris. Ten of the latter were already treated by the conventional daily method and their lesions were well controlled by a carefully established daily maintenance dose. The additional 4 received the alternate-day treatment directly after their lesions were first controlled by the daily method. The follow-up of our cases revealed the following: (a) the adverse reactions to this regimen were comparatively mild and rare, and most of the already existing ones improved or disappeared totally, (b) the endogenous pituitary adrenal function was well preserved and in 3 it returned to normal following its depression by the daily method, (c) the treatment was apparently as effective as the daily devided doses regimen, (d) in 1 patient with pemphigus vulgaris the treatment failed to bring a primary remission, however, it was effective in maintaining the remission achieved by the daily method.