Agility is an important ability in team sports. However, there is a lack of research that analyzed the effects of training on changes in reactive and non-reactive agility in basketball players. The aim of this study was to determine the changes in reactive agility under the influence of a programmed conditioning training process for basketball players. An additional aim of the research was to establish the correlations between predictive variables of explosive strength such as sprint, vertical jumps, reaction speed and morphological characteristics on reactive and non-reactive agility in young basketball players. The research was conducted on a selected sample of junior basketball players aged 16 to 18 (n = 58). Subjects were randomly alocated in experimental (n = 35) and control (n = 23) group. The experimental group (during the training program), after the introductory part of the training which consisted of warming and dynamic stretching, performed twice a week for 15 to 20 minutes of neuromuscular inervation on a ladder for agility with explosive accelerations and sport-specific (situational) conditioning exercises in order to develop and improve the reactive agility with the represented "stop'n'go" movements. The control group conducted a standard basketball training with the associated conditioning training. The variables included six morphological characteristics, six motor tests, and two sport-specific agility tests. The reliability of the tests was checked by calculation of the intraclass coefficient (ICC), coefficient of variation (CV) and typical error of measurement. Two-factor analysis of variance for repeated measurements (Group x Time) was used to determine the effect of the treatment. Correlation and regression analysis were used to establish correlation between variables. The results indicated a high reliability of the tests. Two-factor analysis of variance showed significant treatment effects, with no differential effects (no Time x Group interaction). In other words, both groups improved their performances in agility tests, but without any distinction in the progress achieved. This absence of differential impact of the program can be explained by the high competitive level of players involved in the study, but by the fact that respondents who conducted the control program were also actively involved in basketball training system. An additional analysis of the correlation between variables suggests that progress in agility measures is realized independently of the changes of sprinting capacity. Further research needs to determine the effects of other forms of training on changes in agility measures in basketball, but also in other sports.