We performed a retrospective diagnostic study of congenital cytomegalovirus (CMV) infection in patients with sensorineural hearing loss (SNHL). CMV DNA in preserved umbilical cords was analyzed using real-time polymerase chain reaction analysis. Of 45 analyzable patients with SNHL, CMV DNA was detected in the preserved umbilical cords of 3 patients, all of whom had bilateral SNHL that lacked a clear onset period. CMV DNA was not detected in any of the patients with sudden SNHL or enlarged vestibular aqueduct-associated SNHL. The features of CMV-associated SNHL were more asymmetric than those of CMV-negative bilateral SNHL.