Evidence indicating that corticosteroid therapy may adversely affect attention and memory in asthmatic subjects is reviewed. The potential impact of corticosteroid dosage levels (high versus low) and treatment regimens (daily versus alternate day) on attention and memory is discussed. Findings indicate that the suppression of ACTH by corticosteroids may have different effects on attention and memory as a function of the sex of the asthmatic patient. The need to establish what the effects of theophylline-induced reductions of cerebral blood flow and cerebral oxygen tension are on higher cognitive processes are outlined. The importance of establishing whether or not medications commonly used for the treatment of asthma create deficits of memory or attention that interfere with medical compliance is emphasized.