Excavation projects in urban areas are encountered with some problems. Thus the engineers should consider an appropriate margin of safety for design and construction. Conventional methods of slope stability analysis are usually based on limit state analysis and factor of safety criterion. These methods do not take into account the uncertainties. It is attempted to utilize the risk based approaches to overcome those deficiencies. In this approach, the safety factor is determined based on the parameters pertinent to uncertainties and level of acceptable risk. These methods can be used to evaluate the risk of failure and the necessary measures to control the risks. Monte Carlo simulation method is a probabilistic assessment tools to quantify the uncertainties. In the present research, slope stability of nailed wall has been investigated utilizing Monte Carlo simulation and the reliability index and probability of failure has been computed.