Introduction: Mumps is a systemic viral infection characterized by swelling of salivary glands, especially the parotid ones. Gonads, meninges, pancreas and other organs may also be affected. Aims of the study: The aim of this study was to analyze the epidemiological characteristics of mumps meningitis in the last epidemic of mumps in the Republic of Srpska, and to analyze the frequency of mumps meningitis and vaccination status in patients who were supposed to be vaccinated against mumps in the war and early postwar period, and also in those patients who were supposed to be vaccinated before or after this period. Patients and Methods: The study included 175 patients divided in the experimental group (140 patients with mumps meningitis) and the control group (35 patients with serous meningitis of other etiology, probably enteroviral). We compared epidemiological characteristics of these patients and additionally we analyzed the differences in these characteristics in patients with different vaccination status. Results: The mean age of patients in the experimental group was 20.0 years (18.0-24.5; IQ), and in the control group 7.0 years (5.0-14.0; IQ) (p <0.001). Patients born between 1985 and 1996 more frequently suffered from meningitis (p <0.001) caused with mumps virus than other patients in the experimental group. There was no statistically significant difference in sex distribution between patients in the experimental and control group (p = 0.746), nor between patients in the experimental group with previously different vaccination status (p = 0.371). Most patients in the experimental group didn't have data of their immunization status. The subsequent are those patients who received only one dose of vaccine, followed by unvaccinated patients and those who were vaccinated correctly. Conclusion: The epidemic of mumps during 2011 and 2012 is a consequence of maintaining the virus in non-vaccinated population (mainly because of the omissions made during the war and early postwar period) and insufficient duration of protection after vaccination, especially in vaccination with one dose of vaccine.