Road slopes in hilly terrains frequently suffer instability due to various anthropogenic and natural loading conditions. The failure of road slopes not only results in significant structural damages but also causes the loss of hundreds of human lives annually. Retaining walls are a type of structure used to support the slopes and make them stable. Mechanically stabilized earth (MSE) wall is a special type of retaining wall constructed using engineered backfill, concrete facia panels, and geosynthetic reinforcements. The existing one-lane road section from chainage: 116 + 400 to 116 + 500 of NH-51, which connects Tura and Dalu, two important cities of Meghalaya state, has been proposed to widen into a two-lane road section. However, earlier studies on the stated chainage shows that the section is recognized as a siking zone and is unstable even in static conditions. In the present study, an MSE wall of height 6.66 m was designed for seismic forces in zone V as per IRC SP:102 (2014). The stability of the road slope with the MSE wall in different loading conditions was analyzed using Slide2 software. The seismic analysis was performed using pseudo-static analysis, considering only the coefficient of horizontal seismic acceleration. Further, the performance of the MSE wall was compared by considering construction demolition wastes (CDW) and steel slag (SS) as sustainable backfill materials. The analysis revealed that the MSE wall with sandy soil backfill was unstable in loading conditions where earthquake and rainfall acted together. Whereas the same MSE wall performed satisfactorily in all assumed loading combinations when the CDW and SS were considered as backfill materials.