Objective: Our objective is to study epidemiology of rotavirus infection in children less than five years during one year in Omdurman Paediatric Hospital. Materials and Methods:The study design was a setting-based study. The required data were obtained by reviewing records of a year in the hospital. Results: The findings revealed that, the total cases of rotavirus infection was 1563, majority of cases occurred among age group 1-12 months 642(41%). About 899(57.5%) of cases were males while 664(42.5%) were females. High percentage 520(33.3%) of diagnosed children came from Umbda. Most of rotavirus cases occurred during April168 (10.7%) and May 158(10.1%), Mild dehydration was found in 1121(71.7%) of cases while 320(20.5%) of patients suffered from severe dehydration. Oral rehydration therapy (ORT) were given to 1120(71.7%) of patients as treatment, intravenous fluids (IVF) to 334(21.3%) and ORT & IVF to 109 (7%). A lot of cases 1110(71%) were improved after received the treatment, 9(0.6%) were died and the rest were still suffering from the clinical features. Conclusion: The study concluded that rotavirus represents a public health problem among children less than five which and effective control measures are needed to minimize this problem.