Diabetes type 1(T1D) is the most frequent form of diabetes in children and young people, which essence is autoimmune destruction of pancreatic B cells islet. Co-occurrence of other autoimmune diseases is observed in children with T1D, the most often are: Hashimoto disease or coeliac disease. We report the case of the patient, who presents coincidence of T1D with other rare autoimmune diseases such as: Graves – Basedow disease, myasthenia gravis, vitiligo and IgA deficiency. All mentioned diseases significantly complicated both endocrine and diabetic treatment of our patient and they negatively contributed her quality of life. The clinical picture of the case allows to recognize one of the autoimmune polyendocrine syndromes: APS-3 and is associated with still high risk of developing another autoimmune disease.