ABSTRACT Objective This study aimed to evaluate the occurrence and clinical predictors of subclinical atherosclerosis in asymptomatic, young adult women with type 1 DM. Subjects and methods The study included 45 women with type 1 diabetes mellitus (DM) (aged 36 ± 9 years) who underwent carotid Doppler ultrasound evaluation to determine the carotid artery intima-media thickness (CIMT) and to assess the occurrence of carotid artery plaques. Insulin sensitivity was assessed by estimated glucose disposal rate (eGDR), and metabolic syndrome (MS) was defined by the World Health Organization criteria. Results The cohort had a mean age of 36 ± 9 years, diabetes duration of 18.1 ± 9.5 years, and body mass index (BMI) of 24.6 ± 2.4 kg/m2. MS was present in 44.4% of the participants. The CIMT was 0.25 ± 0.28 mm, and the prevalence of carotid artery plaques was 13%. CIMT correlated positively with hypertension (p = 0.04) and waist-to-hip ratio (r = 0.37, p = 0.012). The presence of carotid artery plaques correlated positively with age (p = 0.018) and hypertension (p = 0.017). eGDR correlated negatively with CIMT (r = -0.39, p = 0.009) and carotid plaques (p = 0.04). Albuminuria showed a correlation trend with CIMT (p = 0.06). Patients with carotid artery plaques were older, had a higher prevalence of hypertension, and lower eGDR. No correlation was found between CIMT and carotid plaques with diabetes duration, MS, BMI, cholesterol profile, glycated hemoglobin, high-sensitivity C-reactive protein, or fibrinogen. Conclusion Insulin resistance, central obesity, hypertension, and older age were predictors of subclinical atherosclerosis in asymptomatic, young adult women with type 1 DM.