Rock slope stability evaluation is complex due to various influencing factors that contribute to the instability of the slope. The stability of the slope depends on the slope geometry, strength of slope forming materials, rock type, discontinuity characteristics, weathering rate, and groundwater condition. Rock masses forming cut slopes usually start to deteriorate after the excavation phase due to stress relief and weathering. Deterioration of cut slopes is one of the parameters that contributes to the instability events of cut slopes. A review on the types of slopes failure, factors of instability, degradation of engineering structures and degradation of rock was carried out and thoroughly presented in this paper. It can be observed from the reviewed studies that the main factors influencing the degradation of rock slope include the history of rock, weathering, surrounding environment and the disturbance caused during the construction stage of projects through or besides the slopes. Degradation in the form of drying and wetting also plays an important role in deteriorating the rock masses resulting in various types of failure. © 2019, Construction Research Institute of Malaysia. All rights reserved.