Background: Despite the efforts of the World Health Organization, some childhood viral diseases, for which there is already an effective vaccine, have not yet been eradicated. Among these, we find varicella, mumps, measles, and rubella, which although in most cases have a benign course, can in some cases be responsible for infectious outbreaks, especially in nosocomial settings. The aim of this study was to verify the immunological situation of a cohort of trainee obstetricians in Campania regarding varicella, mumps, measles, and rubella to be used as an example for the evaluation of possible preventive strategies to avoid infectious outbreaks. Methods: All the samples collected and sent to the laboratory were eligible for analysis and have been included in the study. Specific IgG for varicella, measles, mumps, and rubella were assayed on serum samples taken from 517 trainee obstetricians using the enzyme-linked immunosorbent assay (ELISA) technique. The seropositivity results were statistically analyzed by correlating them to age group and gender. Results: The results obtained show that a percentage of trainee obstetricians tested do not have an effective immunological coverage against at least one of the vaccine-preventable diseases considered, especially for mumps. Conclusions: Therefore, it is proposed to extend surveillance to other professionals in contact with frail patients and increase awareness of vaccination campaigns.