The study of the slope stability within and around the reservoir of the proposed Basara dam near Delaizha village, Sulaimaniyah District, Kurdistan Region, NE Iraq is carried out. To evaluate the stability of slopes in the studied area, sixteen stations were selected within and in the vicinity of the reservoir area, fourteen stations in the rock slopes, and two stations in the soil and talus sediments.In this study, the stability of the rock slopes have evaluated by a new system, known as Landslide Possibility Index (LPI), as well as the approach of Hoek and Bray for those stations that are near the proposed dam site and need a detailed study. Moreover, the soil and talus slopes have evaluated by conventional methods.The application of the LPI system leads to the conclusion that the possibility of failures and the degree of hazard in the eight rock slopes, Stations No. 2, 5, 8, 9, 11, 12, 13 and 15 is Moderate, while in the six remained rock slopes, Stations No. 1, 3, 4, 6, 7 and 10; the possibility of failures and the degree of hazard is High.Detailed study of rock slopes in the vicinity of the proposed Basara dam (Stations No. 1 and 2) revealed that they are unstable, where toppling, rock fall, rock rolling have occurred. Further failures will occur in the future, which might affect the stability of the dam, because during toppling and/ or rock fall; some of the blocks may roll down into the reservoir of the dam, when it is filled by water, where the consequences will be very hazardous.The study of the soil and talus slopes revealed that soil slump had occurred in Station No. 14, which is recognized by leaning of the trees down slope and the moved soil left a scar due to movement. While in the talus slope (Station No. 16) rock rolling and falling have occurred, because the slope has a direct contact with the valley floor and being continuously under-cut by water currents during floods, thus the water currents have removed, the fine materials between large blocks.