Aim. We investigated the relationship between irisin concentrations and glycemic control, body composition and anthropometric measures in children with type 1 diabetes mellitus. Methods. The study involved 40 subjects with T1DM prospectively. Glycemic control was evaluated. Body composition was analyzed with a bioimpedance analyzer (BIA). Serum irisin concentrations were measured using an ELISA kit. Results. Irisin levels were found higher in BMI <17 kg/m2 group (p=0.002) compared to BMI >17 kg/m2. Irisin level was negatively correlated with weight, height, BMI, fat free mass, skeletelal muscle mass, basal metabolic rate (r=-0.40, p= 0.011; r=-0.32, p=0.046; r=-0.366, p= 0.022; r=-0.423, p= 0.007; r=-0.430, p=0.006; r=-0.416, p=0.009, respectively); there was a strong correlation between LDL-C and irisin levels (r=0.367, p=0.02). In multivariate linear regression analyses model, irisin concentrations were correlated with weight (ß-coefficient=-0.391, p= 0.015). LDL-C is associated, but not correlated significantly with irisin levels, (ß-coefficient =0.272, p=0.084). Conclusion. As a result, weight and LDL-C were the predictors of circulating irisin. To our knowledge, this study is the first examining association between irisin levels and body composition comprehensively, in children with type 1 diabetes mellitus.