Introduction Data on the pattern of admissions and causes of child death are crucial in informing priorities for improving child survival. In many health facilities in sub-Saharan Africa, understanding the pattern of paediatric admissions and their outcomes is constrained by poor documentation of these important features. Methods We developed and piloted a simple paper-based tool for documentation of basic, standardised patient-level information on causes of admissions, diagnoses, treatments and outcomes in children admitted to a rural hospital in Sierra Leone. The tool contained sections covering basic sociodemographic information about a patient, chief medical complaints, findings from clinical examinations and tests conducted at admission, results from subsequent clinical and laboratory investigations, working/definitive diagnoses, management and treatment outcomes. Results From 1 August 2019 to 31 July 2021, we used this tool to document the admissions, treatments and clinical outcomes of 1663 children admitted to Kambia district hospital in northern Sierra Leone. The majority of the children (1015, 62%) were aged 12–59 months, were boys (942, 57%), were wasted (516, 31%), stunted (238, 14%) or underweight (537, 32%). Above a half of the children lived more than 1 km distance from the hospital (876/1410, 62%). The highest number of admissions occurred in November 2019 and the lowest in April 2020. Severe malaria was the leading cause of admission. More than 80% of the children were successfully treated and discharged home (1356/1663, 81.5%) while 122/1663 (7.3%) died. Children aged under 5 years who were underweight, and those who presented with danger signs (eg, signs of breathing difficulty, dehydration, head injury or severe infections) had a higher risk of death than children without these features (p<0.01; p=0.03; p=0.011 and p=0.009, respectively). Conclusion Lack of systematic documentation of medical histories and poor record keeping of hospital admissions and outcomes can be overcome by using a simple tool. Continuous use of the tool with regular audits could improve delivery of paediatric care in resource-limited settings.