Purpose: Little information is available on joint kinematic adaptations during walking on cross-slope surfaces (i.e. a surface incline perpendicular to the direction of locomotion). This study aimed to evaluate the effects of cross-slope surfaces on three-dimensional (3D) kinematics of hip, knee, and ankle joints during stance phase of walking. 
Methods: This is a quasi-experimental study. Ten healthy adult male students were selected through available sampling method and walked along an inclinable walkway in both level (0°) and cross-slope (10°) configurations. The 3D angles of hip, knee, and ankle along with their time of occurrence (the time reaching to the maximum values for each specific joint angle) were analyzed using repeated measures multivariate analysis of variance (MANOVA) by SPSS 17. P<0.05 was considered significant. 
Results: Knee and ankle joints had the most kinematic adaptations on cross-slope conditions in the sagittal plane, while in the transverse plane angles of hip and knee joints were mainly altered (P<0.05). These adaptations are necessary to adjust the functional leg-length during different stance phases to both maintain a subtle gait pattern and medio-lateral balance. Though significant differences in timing of the joints kinematic events between level and cross-slope walking were observed (P<0.05), their temporal aspects of the kinematic adaptations were more consistent than their magnitude. 
Conclusion: The information obtained from this study enriches our understanding about the kinematic adaptations of the lower extremity joints in stance phase during level and cross-slope walking.