The objective of the study is to assess coronary artery calcification (CAC) among adolescents with type-1 diabetes and to determine its relation with high-sensitivity C-reactive protein (hs-CRP), dyslipidaemia, glycaemic control and microvascular complications. The study included sixty patients with type-1 diabetes. Their ages ranged from 12 to 18 years and their diabetes duration ranged between 10 and 15 years. Patients were compared with 60 healthy subjects who served as controls. Clinical examination and laboratory investigations were done for evaluation of glycaemic control and presence of microvascular complications. Lipid profile, hs-CRP and multislice spiral computed tomography were done. Hs-CRP, total cholesterol, triglycerides and low-density lipoproteins levels were significantly higher in patients with diabetes compared to controls (P < 0.001). Twelve patients with diabetes (20%) had positive CAC. The mean calcium score was significantly higher in patients with diabetes compared to controls (P < 0.05). Smoking significantly affects CAC as 50% of smokers with diabetes had evidence of CAC compared to 9.1% of non-smokers with diabetes (P < 0.001). Fifty percent of patients with diabetes on angiotensin-converting enzyme inhibitor (ACEI) had evidence of CAC compared to 0% of patients without history of ACEI therapy (P < 0.001). Diabetics with CAC had significantly elder age, longer disease duration and higher mean glycosylated hemoglobin compared to diabetics without CAC (P < 0.05). Blood pressure percentiles, albumin creatinine ratio and serum lipids were significantly higher in patients with CAC compared to those without CAC (P < 0.001). All diabetics with severe retinopathy had positive CAC compared to 0% with normal Fundus (P < 0.001). All diabetics with overt nephropathy had positive CAC compared to 13.3% and 0% in micro- and normo-albuminuric patients (P < 0.001). Young patients with diabetes have evidence of CAC. Smoking, microvascular complications and dyslipidaemia might contribute to this risk.