To determine gender differences, positional differences, and patterns of change in the performance of the basketball line-drill test, 93 male (mean age 16.8 years, s챮1) and 95 female (mean age 16.5 years, s챮0) basketball players undertook 516 line-drill tests over a 5-year period. Log-transformed performance times were analysed using a mixed model that included quadratic within-participant fixed effects for time in the season and time in the programme. Changes and differences were standardized for interpretation of magnitudes. Mean performance times were 28.0 s (s챮3) for males and 30.4 s (s챮3) for females. The mean pattern of change in performance within a season differed substantially between the sexes and playing positions: male guards and female centres showed moderate to very large improvements mid-season of 1.1% and 3.5% respectively (90% confidence limits +2.1% and +3.0%), while female guards and male forwards showed large to very large decrements of 71.6% (+2.6%) and 72.4% (+2.0%). Over 3 years, males improved performance across all three playing positions by 1.4% (+1.3%) and females by 2.9% (+1.4%). Males improved performance by 0.2% (+0.5%) per year, whereas the performance of females deteriorated by 0.6% (+0.4%) per year. The differing patterns of performance change presumably reflect variations in training and competition loads, with short-term fluctuations in performance being managed to promote longer-term improvements.