Meningitis is the most common infectious disease of the central nervous system both in children and in adults. The incidence of the disease in Poland, similar to Western Europe, is 6–8 cases per 100,000/year, with the highest figure for children up to 4 years of age. Aim of the study: The aim of the study was to make a detailed analysis of aseptic meningitis cases in children, with a focus on aetiology and course of the disease, and laboratory results. Materials and methods: A retrospective analysis was performed on a group of 59 children aged between 2.5 months and 17 years in whom aseptic meningitis was diagnosed based on clinical evaluation. Results: Between May and October 2018, 44 children aged 7.99 ± 3.93 were hospitalised with the diagnosis of nonpyogenic (aseptic) meningitis. In 9 patients (20.5%), enteroviral neurological infection was found, and in 8 (18.2%) Borrelia burgdorferi, in 5 (11.3%) EBV and in 2 (4.5%) HHV-7 neurological infection was diagnosed. For 20 children (45.5%), the cause of infection could not be established. The longest hospitalisation time was associated with Lyme neuroborreliosis. In the same months of 2017, 15 patients were hospitalised at our department with aseptic meningitis. The numbers of cases for different causes were: undetermined – 9 patients (60%), enteroviral – 2 (13%), EBV – 2 (13%), Parvovirus B19 – 1 patient (7%) and VZV – 1 patient (7%). Conclusions: In 2018, a threefold increase was observed in the number of hospitalisations associated with aseptic meningitis in relation to the same period of 2017, with a lasting predominance of boys. Most frequently, the aetiology was undetermined. Among the cases in which the cause was established, the most common aetiology was enteroviral. In 2018, unlike in 2017, cases of hospitalisation for neuroborreliosis were recorded. Incomplete utilisation of the polymerase chain reaction method was considered to be one of the causes of insufficient identification of neurotropic pathogens. A general examination of the cerebrospinal fluid did not differentiate between causes of aseptic meningitis.