BACKGROUND Little is known about the clinical importance of cytomegalovirus (CMV) antigenemia for intrauterine-CMV-infected newborns. The aims of the present study were to evaluate the diagnostic accuracy of CMV antigenemia during the neonatal period and its association with clinical manifestations. METHODS CMV antigenemia was analyzed using neonatal blood from 25 patients suspected of having intrauterine infection because of abnormal clinical manifestations in the mother, fetus, and newborn. Neonatal urine samples were collected for diagnosis of intrauterine infection. The diagnostic accuracy of the antigenemia analysis was evaluated by comparing it with the results of urinary CMV analyses. The clinical manifestations of antigenemia-positive and -negative infected newborns were compared in the infected newborns. RESULTS Fifteen newborns were congenitally infected and 10 were uninfected as diagnosed on virus isolation from neonatal urine. Six of 15 infected newborns were positive for CMV antigenemia. CMV antigenemia had a positive predictive value of 100%, a negative predictive value of 52.6%, a sensitivity of 40%, and a specificity of 100%. CMV retinitis and pneumonitis were more prevalent among antigenemia-positive newborns (4/6) than antigenemia-negative newborns (0/9; P < 0.05). CONCLUSIONS Antigenemia was significantly associated with retinitis and pneumonia, but it was not sensitive enough to diagnose intrauterine CMV infection.