Background: Few studies have evaluated the details of insulin therapy for type 1 diabetes mellitus (T1D) in Chile. Aim: To describe clinical features and treatment details of adults with T1D and its association with metabolic control. Material and methods: Review of medical records of patients with T1D treated in a clinical network. Demographic and clinical features, types and doses of insulin and glycated hemoglobin levels were registered. The use flash glucose monitors (FGM) and insulin pumps (CSII) were also recorded. Results: 205 records were reviewed, with T1d lasting 12 ± 10 years. Twenty six percent had hypothyroidism, 1% had celiac disease, 12% had hypertension, 20% had dyslipidemia; 13% had diabetic retinopathy, 2% had diabetic nephropathy, 8% had neuropathy and 2% cardiovascular diseases. Mean body mass index was 25 kg/m2 and mean glycated hemoglobin was 8%. Eighty-two percent used multiple daily injections, 18% used CSII and 24% used FGM. As basal insulin, 35% used slow acting analogs and 65% used ultra-slow analogs. As rapid acting insulin, 69 patients used Lispro, 79 Aspart and 50 Glulisin. Bolus doses were calculated using only capillary glucose in 22%, while 78% also considered carbohydrate consumption. Variables significantly associated to better control were the use of carbohydrates for dosing rapid insulin (A1c 7,85% vs 8,59%, p=0,008), use of CSII (A1c 7,36% vs 8,16%, p=0,008), and basal doseBackground: Few studies have evaluated the details of insulin therapy for type 1 diabetes mellitus (T1D) in Chile. Aim: To describe clinical features and treatment details of adults with T1D and its association with metabolic control. Material and methods: Review of medical records of patients with T1D treated in a clinical network. Demographic and clinical features, types and doses of insulin and glycated hemoglobin levels were registered. The use flash glucose monitors (FGM) and insulin pumps (CSII) were also recorded. Results: 205 records were reviewed, with T1d lasting 12 ± 10 years. Twenty six percent had hypothyroidism, 1% had celiac disease, 12% had hypertension, 20% had dyslipidemia; 13% had diabetic retinopathy, 2% had diabetic nephropathy, 8% had neuropathy and 2% cardiovascular diseases. Mean body mass index was 25 kg/m2 and mean glycated hemoglobin was 8%. Eighty-two percent used multiple daily injections, 18% used CSII and 24% used FGM. As basal insulin, 35% used slow acting analogs and 65% used ultra-slow analogs. As rapid acting insulin, 69 patients used Lispro, 79 Aspart and 50 Glulisin. Bolus doses were calculated using only capillary glucose in 22%, while 78% also considered carbohydrate consumption. Variables significantly associated to better control were the use of carbohydrates for dosing rapid insulin (A1c 7,85% vs 8,59%, p=0,008), use of CSII (A1c 7,36% vs 8,16%, p=0,008), and basal dose