Kettlebell swing makes tehnical base in majority of kettlebell exercises, but it is often used on its own as a tool in various training programs that develop strength, power, muscular endurance as well as aerobic capacity. Two main styles of this exercise are russian and american one. Main goal of this paper was to determine which one of these styles offers greater mechanical output in form of power, velocity and momentum when energy expenditure and injury risk are taken into consideration and in addion which style represents the safer variant of training operator for developing certain strength and power qualities along with muscular endurance. Selected population of physicaly active males (n = 15) performed kettlebell swing under two conditions: using russian (1) and american (2) styles. They performed 8 swings using a 24 kg kettlebell ( ~25% bodyweight) during which both the concentric and eccentric phases of the lift were analyzed. Results of t- test for dependent samples show a statistically significant difference between conditions 1 and 2 in duration of concentric portion of the lift (p < 0,01), amplitude (p < 0,01), as well as momentum during eccentric portion of the lift (p = 0,001). There was no statistically significant difference in power variable (p = 0,681), i.e. the results indicate that american style has longer cycle duration, amplitude and momentum but power genereted during both styles remains simmilar. In conclusion, both styles have their rightful place in training protocols for developing strength, power and muscular endurance for athletes as well as amateurs but russian style presents safer alternative because of practically equal benefits which are attained in safer manner