Cefepime is a fourth-generation cephalosporin with a broad antimicrobial spectrum and good activity against both gram-positive and gram-negative organisms. We present the case of a 61-year-old man who developed an immediate urticarial reaction after receiving a single dose of cefepime. Skin tests were positive to cefepime and negative to the other beta-lactam antibiotics. Controlled administration of amoxicillin-clavulanic acid and ceftazidime was well tolerated by the patient. To the best of our knowledge, this is the first report of selective hypersensitivity to cefepime demonstrated by skin and challenge tests. Complete allergological studies, including challenge tests with other beta-lactam antibiotics that produce a negative result in skin tests, should be considered in these patients.