From 1 January 1995 to 31 December 2004, 22 patients (13 males, nine females; age range 2-12mo) with infantile spasms and cytomegalovirus (CMV) infection were treated with intravenous ganciclovir (GCV) and antiepileptic drugs. GCV was given for 3 to 12 weeks with a 1-month interval (one, two, or three courses). Epileptic spasms occurred before (group A: eight patients), simultaneously (group B: eight patients), and after (group C: six patients) a diagnosis of human CMV (HCMV) infection and antiviral treatment. In 11 patients, DNA HCMV was found in cerebrospinal fluid by nested-polymerase chain reaction method (neuroinfection). All infants excreted CMV in urine. DNA HCMV and specific immunoglobulin M and immunoglobulin G antibodies were present in blood. Ten patients, including four with neuroinfection, have been seizure-free for at least the past 18 months. In two patients with neuroinfection, vigabatrin monotherapy was withdrawn after a 2 year 6 month seizure-free period. Eighteen patients required antiepileptic drugs polytherapy, four of whom required additional adrenocorticotropic hormone (ACTH). Six patients on polytherapy were seizure-free on follow-up, two of whom were treated with ACTH, but no patient with hypsarrhythmia who required ACTH treatment was seizure-free on follow-up. In five patients, psychomotor development was normal, 16 had tetraplegia (Gross Motor Function Classification System [GMFCS] Level V), and one had diplegia (GMFCS Level III). Early antiviral and antiepileptic therapy could result in the long-term cessation of seizures.