The stability analysis of reinforced wall (RW) for external failure mode is performed in the present study using the surrogate based probabilistic model. The sliding mode of failure is considered because it is the critical mode of failure of reinforced wall in the external stability analysis. The stochastic response surface method (SRSM) is used under pseudo-static conditions for the probabilistic analysis, owing to its accuracy and efficiency. The soil internal friction angle (ϕ) and specific weight (γ) serve as the random variables. The effect of randomness of the random variables on the stability of RW is illustrated. The plots depict that the probability of failure (Pf) of RW increases with the increase in uncertainty of the random variables. Moreover, the accuracy of the SRSM is compared with the Monte-Carlo simulation (MCS) technique. The results show that the SRSM is highly accurate and efficient in examining the stability of the RW.