BACKGROUND: Optimal body composition is a critical factor to successful performance in elite artistic swimming. Therefore, a reliable method is required for prediction of percentage (%) of body Fat Mass (FM) or Adipose Tissue Mass (ATM), which influences the execution of artistic movements and body displacements, in / out of the water. Increased levels of FM produce higher energy cost, affect Lean Body Mass (LBM)/FM relationship, physical overloading and potential risk of musculoskeletal injuries. PURPOSE: Compare two methods to determine % of FM, based on the sum of 6 Skinfolds (SUM6SF): a) Two Component Model (2-CM), using M. Yuhasz equation (1974); b) Five Component Model (5-CM) derived from Fractionation of Body Mass (D. Kerr, 1988). METHODS: Sixteen young athletes from Artistic Swimming's Argentine National team were evaluated voluntarily in this study (age: 16.76 ± 2.74 years; Weight: 60.59 ± 10.88 Kg; Height: 165.79 ± 7.26 cm; BMI 21.92 ± 2.60; SUM6SF 79.28 ± 22.73). The anthropometric variables measured were Weight, Height, Sitting Height and 6 Skinfolds (triceps, subscapular, supraespinale, abdominal, thigh and calf). We applied matched t-test to determine statistical differences (SD) between 2-CM and 5-CM at p < 0.05. RESULTS: % of FM predicted by 5-CM was 30.01 ± 2.74 %, while % of FM predicted by 2-CM was 15.85 ± 3.52 % (SD at p < 0.01). Although the values have moderate relationship (r) of 0.87 (reasonable, because both equations used the same SUM6SF), 2-CM is an equation derived from Hydrodensitometry (like Siri's formula), which underestimate significantly FM, compared with 5-CM (derived from cadaver studies), which represents a multi-component model, that (additionally) calculate muscle, bone, residual and skin compartments, predicting total weight compared with scale values (r = 0.95, previously published). CONCLUSIONS: Based on the results, we conclude 5 CM could be more precise and effective to quantify body FM, determine better LBM/FM, looking for best technical performance, increasing mechanical efficiency and reducing incidence of musculoskeletal injuries.