Background: The aims of the study were (i) to identify the physical fitness and basic anthropometric characteristics of Polish female basketball players aged 13 to 15 years, (ii) to show the effect of maturity timing on the performance in motor tests and basic body composition parameters, (iii) to identify the index that contributes most to the prediction of performance in the tests of speed, jumping ability, agility, and endurance. Methods: The sample included 925 female Polish players (U13-15). In part 1, maturity timing category distribution were examined within across age-groups. In part 2, the relationship between the anthropometric variables, physical fitness performance was assessed based on maturity timing categories (ANCOVA analysis). In part 3, backward stepwise multiple regression analyse quantified the relationship between maturity timing (group of PHV) and physical performance.Results: ANCOVA results (age, body height, and body mass as covariates) showed in the U13 female basketball players significantly higher sprinting (20m), jumping ability and endurance tests results of the PHV1 group.Better results was observed in U14 female players in PHV1 compared to PHV2 and PHV3 in 20m and jumping tests but opposite trend was observed for 5m sprint and endurance test (distance covered and VO2max). U15 basketball players from the PHV3 group were characterized by better results of jumping abilities, endurance, 10m and 20m sprint and agility (total, S4) tests. Maturity timing (10m), chronological age (5 m, 20 m, agility, SVJ, VJ, and VO2max tests), body height (10m), body mass (10m, 20m, VJ, VO2max), and the interaction between body mass and height (SVJ) were significant (adjusted R2 = 0.02-0.10; p < 0.001) predictors of motor skills. Conclusion: The results can help the coaches to personalize training programs and to adapt the training content to the biological age of the players.