For stability analysis of slopes, factor of safety values determines the failure criteria. Limit equilibrium concept is preferred for analysis of two-dimensional model for its simplicity and sufficient accuracy. This method generally involves two main steps: (a) calculating the safety factor for a starting slip surface, and (b) utilizing optimization techniques to find the critical slip surface with the lowest safety factor. Different limit equilibrium methods assume sliding mass to be rigid and divide it into several vertical slices or blocks. However, vertical failure surfaces are not always predominant, especially for rock masses. The Sarma method (Sarma in J Geotech Eng Div ASCE 105:1511–1524, 1979) offers a more advanced and rigorous approach for both static and seismic slope stability analysis. The Sarma method divides the sliding mass into discrete blocks with inclined interfaces under designated earthquake loads Despite its advantages, the Sarma method is not typically used to find the critical slip surface because it requires numerous iterations to determine the optimal set of slice inclinations, making the process quite laborious. To address this, an attempt has been made to analyze four well-known slope stability problems from the literature (Hassan and Wolff in J Geotech Geoenviron Eng ASCE 125:4, 301–308). Each problem is first analyzed utilizing two established methods (Spencer and M & P) with the same initial trial surface. The critical slip surfaces are identified through optimization, taking varying seismic effects into account. The optimized slip surfaces are then re-evaluated utilizing the Sarma method and optimized. All the analysis is performed utilizing GEO 5 software. The final factor of safety is found to be on the higher side for all the cases.