Background Diabetic complications have been identified as the major cause of morbidity and mortality in persons with type 1 diabetes mellitus. Lack of appropriate glycaemic control is a significant risk factor for the onset and progression of long term complications of diabetes. Identifying the determinants of glycaemic control is therefore imperative. Aim To identify the socio-demographic determinants of glycaemic control among children with type 1 diabetes mellitus in south eastern Nigeria Method It was a cross-sectional hospital-based study of children aged 3-18 years with T1DM. Seventy-one children with type 1 diabetes mellitus were consecutively enrolled after obtaining consent. A questionnaire was completed recording their demographic variables and their HbA1c was estimated. Result There were 71 subjects with type 1 diabetes mellitus enrolled. 38 (52.5%) of them were males. Mean age (years) was 13.7±0.3. Mean age at onset of diabetes was 11.6 years (range 3-16), mean duration of diabetes was 2.3 years (range 0.4-8 years), mean HbA1c value was 10.5% (range 6.4%-14%), Age, age at onset of diabetes, duration of diabetes and caregivers involvement in diabetes management were strong determinants of glycaemic control (p<0.05). Conclusion Younger age, young age at onset of diabetes, and short duration of diabetes and caregivers involvement in diabetes management were strong indicators for better glycaemic control.