Background Increased cardiovascular morbidity in type 1 diabetes mellitus (T1DM) may be due to vascular endothelial dysfunction, accelerated thickening of arterial intima, and changes in the ventricular functions. Aim The study aimed to describe the frequency and the pattern of dyslipidemia in children and adolescents with T1DM, and its relation to the degree of glycemic control, regular activities, and the duration of diabetes. Patients and methods This case–control study included 50 patients with T1DM, aged more than or equal to9years,withmorethan1-yeardurationofdiabetes,and39healthyage-matched and sex-matched children as controls. All participants were subjected to the following: full history taking, full clinical examination, and investigations including glycatedhemoglobin,totalcholesterol,low-densitylipoprotein-cholesterol(LDL-C), high-density lipoprotein-cholesterol (HDL-C), and triglycerides. Results Therewasahighstatisticallysignificantincreaseinthefrequencyofdyslipidemiain diabeticpatients(64.0%).Twenty(50%)patientshadelevatedLDL-C,withamean of 102.0±34.4mg/dl; the most common type of dyslipidemia was high LDL-C and lowHDL-Cineight(25.0%)patientsfollowedbyisolatedhighLDL-Cinsix(18.75%) patients, isolated low HDL-C in five (15.63%) patients, and hypercholesterolemia and high LDL-C in four (12.50%) patients. There was no statistically significant differencebetweenthedyslipidemiagroupandthenormolipidemicgroupregarding BMI (P=0.070), but waist circumference showed statistically significant increase in the dyslipidemic group compared with the normolipidemic group (P=0.045). As regards the degree of activity affecting the lipid profile, as in the normolipidemic group, 94.4% were practising mild regular activities, whereas in the dyslipidemic group, only 62.5% were practicing mild regular activities (P=0.041). Conclusion OurstudysupportthehypothesisthatLDL-Cis the ‘cornerstone’ forassessmentof lipoprotein-related cardiovascular risk. In addition, activity is important for the prevention of dyslipidemia, and waist circumference is an easily obtainable measure of abdominal adiposity.