Seed germination percentage of Kusum (Schleichera oleosa Merr.) was examined with 5 pre-sowing treatments in the nursery of Bangladesh Forest Research Institute and growth performances of seedlings were determined in the nursery and field condition. The main aims of the study were to determine the effect of different pre-sowing treatments on seed germination and seedlings growth performance in nursery and field condition. The pre-sowing treatments were: i) soaking of seeds in tap water for 12 hours, ii) soaking of seeds in tap water for 24 hours, iii) soaking of seeds in tap water for 36 hours, iv) soaking of seeds in tap water for 48 hours and v) control (0 hour). The seeds after soaking were sown in the seed bed directly in the nursery. Seed germination percentage were significantly (p < 0.05) influenced by pre-sowing treatments and the highest germination (72%) was obtained when soaked for 36 hours, and the lowest (48%) was in control. With treatment (T3), the maximum shoot length (12.8 cm), root length (11.6 cm), and vigor index (1171.2) were noted. The young seedlings were transferred after 30 days of germination having 3-4 leaves from seed bed to polybags (15×23 cm size) filled with soil and cow dung at 3:1 ratio by volume. Survival percentage of seedlings was maximum (96%) at 2.00 in x 2.00 in spacing in the field and maximum height 105.54 cm 12 months after out-planting. The results of the study suggest the pre-sowing treatment of seeds in tap water for 36 horn s was most effective treatment for higher germination percentage and out-planting of one year old seedlings at 2.00 m x 2.00 m spacing in the field for better growth performance of S. oleosa seedlings.