Five cases of at-risk neonates for severe varicella infection were reported. Intravenous immunoglobulin (IVIG) was given soon after birth in different ways to four of them (Case 1 received 400 mg/kg/day for the first three days of life; Case 2 received a single dose of 200 mg/kg on day 2, and another dose of 160 mg/kg on day 7; Cases 3 and 4 received 400 mg/kg on day 2). All five patients were given acyclovir therapy, 40 to 45 mg/kg/day for five to nine days. (Case 1 for prophylaxis, Cases 2, 3, 4, 5 for treatment). Case 2, 3, 4, 5 developed vesicular rash, mild to moderate in degree, with rapid resolution without any constitutional symptoms. Case 1, who received both IVIG and acyclovir for prophylaxis, had no vesicle occurrence. IVIG, in combination with acyclovir, is a safe and probably effective regimen for preventing severe varicella in at-risk neonates. A multi-centered, collaborative study is mandatory to study the efficacy of prophylactic acyclovir with IVIG in these neonates.