OBJECTIVE To determine patterns of admissions due to diarrhea and their outcomes of paediatric patients at Muhimbili National Hospital (MNH). METHODOLOGY A hospital-based prospective study including all children admitted to the Diarrhea Unit during the study period. Data was collected using content analysis checklists. Ethical clearance was sought from MNH and confidentiality in handling the information was observed. Data was analyzed using Epi-info 2002 statistical software. RESULTS A total of 50 children were admitted during the study period. Acute watery diarrhea was the commonest type of diarrhea (90%). Most of the patients stayed in the ward for 4 to 10 days. Commonly associated diseases apart from diarrhea were found to be malaria, pneumonia and malnutrition. Over half of children succumbed to the illness. CONCLUSION The diarrhea mortality among children at the MNH diarrhea unit as reflected in this study was very high.