<p>There have been many studies exploring the rainfall induced slope failures in the earthquake affected terrain. However, studies evaluating the potential effects of both landslide triggering factors; rainfall and earthquake have been infrequent despite the rising global landslide mortality risk. The SE Carpathians, which have been subjected to many large historical earthquakes and changing climate and thus resulting in frequent landslides, is one such region that is least explored in this context. Therefore, a massive (~9.1 Mm<sup>2</sup>) landslide, situated along the Basca Rozilei River, in the Vrancea Seismic Zone, SE Carpathians is chosen as a case study area to achieve the aforesaid objective. The present state of slope reveals the Factor of Safety in a range of 1.17–1.32 with a static condition displacement of 0.4–4 m that reaches up to 8–60 m under dynamic (earthquake) condition. The Groundwater (GW) effect further decreases the Factor of Safety and increases the displacement. Ground motion amplification enhances the possibility of slope surface deformation and displacements. The debris flow prediction, implying the excessive rainfall effect, reveals a flow having 9.0–26.0 m height and 2.1–3.0 m/sec velocity along the river channel. The predicted extent of potential debris flow is found to follow the trails possibly created by previous debris flow and/or slide events.</p>