Fourteen generally healthy children (5 females, 9 males, ages 18 months to 13 years) who have developed 2 to 5 attacks of chickenpox are described. Herpes zoster also occurred in 2 of 14 children. No case of chickenpox was severe or associated with complications. General studies of immunoglobulins, specific antibodies to immunization agents, complement and lymphocyte subpopulation number and function indicated that 1 of 14 had low serum IgA and 3 of 14 lacked antibody to 1 (n = 2) or 2 (n = 1) immunization agents. Varicella-zoster virus (VZV)-specific immune studies showed that the children developed VZV-antibody titers by enzyme-linked immunosorbent assay of 1:640 to 1:10 240. By immunoblot assay all appeared to develop a normal spectrum of antibodies to individual VZV proteins. All but one developed VZV cellular immune responses with stimulation indices ranging from 3.6 to 174. Sequential follow-up of 8 patients revealed 1 who became seronegative and 2 who lost VZV cell-mediated immune responses. Chickenpox may recur more frequently than is generally recognized. General and VZV-specific immune investigations are unlikely to indicate a reason.