Concave slopes are generally encountered in circular open excavations which are made for various applications such as open-cast mining, water reservoirs, construction of foundations, underground storage structures, etc. In the present study, stability of a homogenous concave slope is determined using finite element (FE) method considering axisymmetric and plane strain conditions. The soil is assumed as linear elastic perfectly plastic with Mohr–Coulomb failure criterion and follows the non-associative flow rule. The stability analysis is performed with varying inside radius of the concave slope (R) and the height of the slope (H). The concave slope with plane strain conditions is applicable at larger R/H ratio. Factor of safety (FoS) is computed by FE analysis using phi–c reduction for both axisymmetric and plane strain conditions corresponding to various R/H ratio of the slope. Regression analysis is carried out to correlate the ratio of FoS in axisymmetric to FoS in plane strain condition (RFS) and the R/H ratio of slope. It is found from the analysis that as the R/H ratio is increased, the value of FoS in axisymmetric condition reduces and approaches the FoS in plane strain condition.