The aim of the research was to analyze anthropometric variables in children with type 1 diabetes mellitus (DM) in relation with the stage of pubertal development at onset of disease and quality of metabolic control over five-year long observation. Diagnosed children were taller than their peers. This especially referred to age group between 4 and 9.5 years. On the whole, weight of the patients and healthy controls did not differ. However, the diagnosed children had substantially lower weight in puberty than healthy controls. Body mass index was significantly lower in the group of diagnosed children on the whole and in puberty. During a five-year long observation patients have had a significant retardation of growth. However, that retardation referred primarily to patients in prepuberty. Growth retardation was more pronounced with bad metabolic control. Growth was satisfactory if onset of disease had been in puberty. A significant weight gain was observed in patients in puberty whereas in those in prepuberty there was no significant change of body weight at the end of five-year long observation. Metabolic control did not affect observed changes. There were significant differences of anthropometric variables between those suffering from type 1 DM and their peers. The differences depended on the age at onset. The disease had a negative effect on growth with onset in prepuberty, whereas in puberty growth was satisfactory. However, puberty was a period in which patients increased their weight excessively. Prepuberty was a period in which growth had been significantly affected by metabolic control.