The prevalence and socioeconomic burden of diabetes mellitus and associated co-morbidities are rising worldwide among children thereby raising a public health concern. Zambia is not exempted as evidenced by factors such as obesity and sedentary lifestyle amongst others. Aim: The aim of this study was to determine the prevalence of diabetes mellitus (DM) among children in Lusaka, Zambia. Methods: A 10-year retrospective cross-sectional design utilising quantitative methods involving a review of patient case files of children aged 18 years and below diagnosed with diabetes mellitus between January 2009 and December 2019 at the University Teaching Hospital (UTH) in Lusaka, Zambia was done. Results: The total number of children that attended the University Teaching Children’s Hospital during the study period was 150, 563 and of those, 745 were diagnosed with diabetes mellitus. This gave a case prevalence rate of 4.9/1000. Type 1 diabetes mellitus (T1DM) was the most prevalent (54%), followed by one which could not be specified and simply diagnosed as DM (41%) and the least was type 2 diabetes mellitus T2DM (5%). The mean age of the children at diagnosis was 11.3 (SD ± 4.03) with 94.7% of the children being ≥ 5 years old. More females in this study had DM 53 (62.1%) than their male counterparts 36 (37.9%). The mean weight of the children was 35.6 kilograms (SD ±1.98), while the mean height and BMI was 1.46 meters (SD ± 0.06) and 20.9 kg/m2 (SD ± 1.93) respectfully. The mean for glycosylated haemoglobin (HbA1c) was 8.48% (SD ± 1.53) while that of random blood sugar (RBS) was 19.3 mmol/L (SD ± 0.85). The most common comorbidity was vision problems (28.6%) with polyuria (25%) being the most frequent clinical feature. Children with DM were mainly managed with insulin (100%) and some coupled with diet (63.2%) and exercise (3.2%). Conclusion: The prevalence rate of DM among children and adolescents was relatively high. Nationwide awareness campaigns and prevention programmes about diabetes in childhood should be instituted and existing ones strengthened through concerted effort from the relevant stakeholders. A multidisciplinary approach through the involvement of Physiotherapists and nutritionists among other health professionals must be encouraged to stem this looming epidemic