The purpose of the research was to test and/or determine the possibility of predicting success in RG performance on the basis of gymnasts' somatotype. One hundred and twenty-six national-and internationallevel rhythmic gymnasts (age: 11.95 +/- 3.09 years, body height: 147.76 +/- 14.61 cm, body mass: 37.75 +/- 11.72 kg, BMI: 16.79 +/- 2.26 kg/m(2), menarcheal age: 13.57 +/- 1.18 years, training experience: 5.88 +/- 2.79 years), divided into five age group categories (22 beginners, aged 7-9 years; 38 intermediate, aged 9-12 years; 26 advanced, aged 12-14 years; 25 juniors, aged 14-16 years; 15 seniors, aged 16 years and older), volunteered to participate in the study. The obtained results show the central somatotype as the dominant type (except for the seniors: mesomorphic endomorph). By means of a Multiple regression analysis the gymnasts' somatotype statistically significant influence on Success was established only in the group of advanced gymnasts and when considering the sample in total (p< 0.00103 and p< 0.00325, respectively), with an explanation of 51%, i. e. 11% of variance, respectively. Also, the Regression analysis emphasized the significant independent contribution of endomorphy to the prediction of Success within each of five age categories, except the beginners, with negative relationship among variables (except the seniors): intermediate (p= 0.048, b=-0.80375), advanced (p= 0.005, b=-0.9930), juniors (p= 0.037, b=-1.02015) and seniors (p= 0.023, b= 2.4164). When considering sample in total, endomorphy and mesomorphy gave the significant independent contribution to the prediction of Success in RG (p= 0.012 and p= 0.009, respectively), with negative relationship among these independent variables and the dependent one (b=-0.54596 and b=0.59399, respectively). This research has confirmed the importance of endomorphy for RG performance, and thus unambiguously emphasized the lack of subcutaneous fat as desirable factor for success in RG.