Background: Determining the proportion of susceptible workers can represent a first step to the biological risk assessment related to measles, mumps, rubella and varicella exposure. This study aimed to assess the immunity against measles, mumps, rubella and varicella viruses in a cohort of female school workers. Methods: A cross-sectional seroepidemiological study in a sample of 263 school workers undergoing routine annual workplace health surveillance program was conducted. As part of the health surveillance program, serum samples were collected and tested for measles, mumps, rubella and varicella IgG antibodies. Results: Overall seropositivity was 90.5%, 85.2%, 94.7% and 97.3% for measles, mumps, rubella and varicella, respectively. In relation to mumps occupation-specific seropositivity, a statistically significant difference was observed, showing the lowest prevalence of protected individuals in other occupation groups. Moreover, in relation to rubella, school workers born in Centre Italy had the lowest seropositivity of protective antibodies and the difference between groups was statistically significant. Measles and rubella seropositivity showed a significant decrease after 2015. Conclusions: This study showed a relevant proportion of school workers susceptible to the aforementioned diseases. These results highlighted the need for proper health surveillance and immunological controls in school workers, especially for females, and provided useful insights to policymakers to select effective strategies aimed at containing the risk of vaccine-preventable diseases at schools.