Often transfusions red blood cells in patients with hereditary anemias lead to iron overload, that can cause endocrine complications, such as growth retardation, hypothyroidism, hypogonadism, and disorders of carbohydrate metabolism.Clinical case 1. A boy with transfusion-dependent (TD) Diamond-Blackfan anemia at 16.3 years presented with impaired fasting glucose, growth hormone (GH) deficiency, hypogonadotropic hypogonadism; GH therapy was initiated. At the age of 16.8 years old secondary hypothyroidism, secondary hypocorticism and diabetes mellitus were diagnosed. At 17.2 years continuous glucose monitoring (CGM) detected glucose elevations up to 11.7 mmol/l. Therapy with GH and testosterone ethers was continued; levothyroxine and cortef were stopped by patient. At 17.9 years height was 163 cm; no data supporting hypothyroidism nor hypocorticism; glycaemia within goal range.Clinical case 2. A girl with TD beta-thalassemia major at the age of 11.5 years presented with GH deficiency; GH therapy has been conducted from 12.8 to 15.3 years of age. At 13.8 years retardation of pubertal development was diagnosed. At 15.0 hyperglycemia 7.2 mmol/l was detected; normal results of oral glucose tolerance test (OGTT) were observed; glycemia elevations were up to 9.5 mmol/l according to CGM data. At 16.0 height was 152 cm; because of pubertal development arrest hormone replacement therapy was prescribed.CONCLUSION. Growth, pubertal and carbohydrate metabolism disorders were diagnosed in patients with TD hereditary anemias, that confirms the necessity of regularly endocrine investigation. To detect impairment of carbohydrate metabolism investigation of fasting blood glucose, OGTT, and CGM is recommended; glycated hemoglobin measurement is not considered reasonable.