Based on clinical features, infantile seborrheic dermatitis (ISD) can be classified as follows: true seborrheic dermatitis (SD), psoriasiform seborrheic dermatitis (Psor SD), and erythrodermic seborrheic dermatitis. We reviewed the records of 72 children who had been affected by ISD several years earlier to investigate the evolution of disease, to evaluate the patients for the presence of new skin lesions, and to study family histories with respect to these conditions. In addition, we attempted to determine if there is any connection among the initial features of ISD and the types of skin lesions, and atopy or psoriasis. On reexamination, our patients previously diagnosed as having SD showed a larger variety of new skin lesions than those who had Psor SD, and 15% had developed atopic dermatitis. Atopic dermatitis was not present at follow-up in the children with previously diagnosed Psor SD. Psoriatic lesions were present in similar percentages in both groups at the time of reevaluation. Investigation of family history was not useful in predicting later development of psoriasis or atopic dermatitis. We conclude that the initial clinical features of ISD may be of prognostic value, and that SD and Psor SD are probably two different clinical entities.