BACKGROUND Pneumococcal infections are an important cause of morbidity and mortality in the world and in Tunisia. Data on the economic burden of these infections are needed to inform decision-making to include pneumococcal vaccinations in routine childhood immunization. OBJECTIVE This study aimed to estimate the medical cost of hospitalizations due to invasive pneumococcal disease (pneumonia and meningitis) among children aged under 15 years old in Tunisia. METHODS A prospective multicentre study was conducted in 15 paediatric departments, across different socio-economic areas of Tunisia, from June 2014 to May 2015. All children aged under 15 years old who were hospitalized for pneumococcal pneumonia or confirmed bacterial meningitis were enrolled. A case report form was completed for every eligible case. Activity Based Costing method was used to estimate the hospital cost. Data entry and statistical analysis were conducted using SPSS, version 20.0. RESULTS During the study period, 727 children were hospitalized for pneumococcal pneumonia and 60 children were hospitalized for bacterial meningitis, among them 21(35%) had confirmed pneumococcal meningitis. The median hospital cost for pneumococcal pneumonia was 353.910 Tunisian Dinars (TND) and TND 1680.632 for pneumococcal meningitis. Using overall data extrapolation, it was estimated that nearly 1091 hospitalizations for pneumococcal pneumonia and 69 hospitalizations for pneumococcal meningitis occurred each year in Tunisian children aged under 15 years of age, incurring total costs of TND 502 079.408. CONCLUSIONS The economic burden of pneumococcal infections seems to be substantial in Tunisia. The estimated costs does not reflect the real costs of this infection. Cost-effectiveness studies would be helpful to inform policy-makers to take appropriate decisions.