Introduction Falls are a serious social problem. The risk of falling is higher for women compared to the male population, which may be resulting from differences in anatomy of the pelvis. Even though there are papers describing pelvis reaction to perturbation differentiating males and females, the perturbation is usually applied in standing position. The study’s aim was to compare selected values describing the pelvis motion while gait perturbation and normal walking, having regard to sex differences. Material and methods The study group included 43 young healthy adults (27 women and 16 men) aged 23±4 years. Motek Grail system was used to record the position of reflective markers placed on subjects’ body. Gait perturbation (trip) was induced by decelerating one of the belts of the treadmill integrated with the system. Three-dimensional kinematic parameters for the left leg stance phase, when the perturbation occurred, and the next stance phase of the contralateral leg was analyzed. Statistical analysis was conducted in STATISTICA software using a two-way analysis of variance and Pearson correlation. Results Statistically significant differences between gait and perturbation were found for each of the analyzed planes. It was also observed that gender influenced the results. Females had greater maximum pelvic tilt and greater rotation to the right compared to men, both for gait and perturbation. Conclusions Based on the obtained results it can be suggested that differences in the anatomy and biomechanics of the pelvis between male and female may be the reason of higher risk of falling while walking in women compared to the men.