OBJECTIVES: Scarce and limited epidemiological, clinical and microbiological data are available regarding paediatric respiratory tract infections in the Kingdom of Morocco, a middle-income country in northwestern Africa. The results of hospital-based surveillance aiming at describing the aetiology and epidemiology of respiratory distress among children <5 years of age are presented. METHODS: Children admitted to the Hopital d\'Enfants de Rabat, Morocco, and meeting the World Health Organization clinical criteria for severe pneumonia were recruited over a period of 14 months and were thoroughly investigated to ascertain a definitive diagnosis. RESULTS: In total, 700 children were recruited for the study. Most frequent clinical diagnoses included wheezing-related conditions (bronchitis/asthma, 46%; bronchiolitis, 15%), while typical bacterial pneumonia was infrequent (only 19% of the cases). Invasive bacterial disease detected by classical microbiology or molecular methods was also uncommon, affecting only 3.5% of the patients, and with an overall low detection of pneumococcal or Haemophilus influenzae type b disease. Conversely, coverage of respiratory viral detection in the nasopharynx was almost universal among cases (92%), with the three most frequent viruses detected being rhinovirus (53%), respiratory syncytial virus (18%) and adenovirus (17%). The overall case fatality rate (CFR) among recruited patients with a known outcome was 4.1% (28/690). CONCLUSIONS: In Morocco, the epidemiological profile of paediatric acute respiratory infections is markedly shifted towards wheezing-related diseases and thus resembles that of high-income countries. However, the high associated CFRs found in this study call for an improvement in preventive and clinical management strategies.