The paper presents a case of 25 female patient, who is a clinical example of a triple comorbidity – she was a preterm child in which at the age of 2 autism spectrum disorder (ASD) was diagnosed, and at the age of 3 type 1 diabetes mellitus (T1DM). The described case is special because autism coincides not only with diabetes, but also with blindness due to retinopathy of prematurity. In such a situation, the choice of the right treatment method has become a clinical challenge. Considering the patients’ health status and life conditions (comorbidity of T1DM, autism and blindness, abusive, not engaged father, difficult financial situation) very good treatment results as far as T1DM is concerned were achieved: her HbA1c values available from last 3 years ranged from 6.5-7.3% Also, regardless of many obstacles and life crises, the patient maintains possibly the best in her conditions, psychological well-being. The paper can be a source of knowledge and inspiration, presenting challenges and possibilities in treatment of people with T1DM, autism, and other comorbidities. From the therapeutic point of view, it indicates that well planned, individualized therapy may be the basis for creating optimal conditions for the development and improvement of the quality of life of patients.