The aim of this study was to analyse changes taking place within selected kinematic parameters of the swimming start, after completing a six-week plyometric training, assuming that the take-off power training improve its effectiveness. Methods: The experiment included nine male swimmers. In the pre-test swimmers performed three starts focusing on the best performance. Next, a plyometrics training programme, adapted from sprint running was introduced aimed at increasing explosive power of the lower extremities; the programme entailed 75 minute sessions conducted twice a week. Afterwards, a post-test was performed, analogous to the pre-test. Spatio-temporal structure data of the swimming start were gathered from video recordings of the swimmer both above and under water. Results: Impulses triggered by the plyometric training contributed to a shorter start time (the main measure of start effectiveness) and glide time as well as increasing average take-off, flight and glide velocities including take-off, entry and glide instantaneous velocities; the glide angle decreased. Conclusions: The changes in selected parameters of the swimming start and its confirmed diagnostic values, showed the areas to be susceptible to plyometric training and suggested, that applied plyometric training programme aimed at increasing take-off power enhances the effectiveness of the swimming start.