Nosocomial transmission of varicella-zoster virus (VZV) is recognized as a significant cause of morbidity in health care workers as well as in high-risk patients. The current study aimed to investigate the presence of VZV antibodies among physicians and nurses, to assess the variables affecting it, and to compare it with previous international studies. Data were obtained by a questionnaire regarding sociodemographic and occupational characteristics and by determination of serum antibodies to varicella-zoster. The seroprevalence of varicella-zoster among the 335 study participants was 94.8% (95%CI: 91.9%-96.9%), with no significant difference between nurses (94%) and physicians (97%). Decreased risk for the virus was observed in workers who immigrated to Israel from the Asia or Africa (OR=0.15; 95% CI: 0.04-0.51). Reduced immunity among these workers remained significant in a multivariate model, which also included age, gender, years of education, number of siblings, and crowding at childhood. Our data suggest that in spite of the high immunity among Israeli physicians and nurses in general, the implementation of small-scale vaccination programs aimed at workers from warmer and tropical areas, should be seriously considered.