Parkia timoriana (DC.) Merr. (Syn. P. roxburghii G. Don.), belongs to the family Mimosaceae, is a multipurpose tree and a delicious vegetable of Manipur. It shows wide variation in seed weight and seed size. The effect of seed weight and seed size on germination, seedling survival and growth were evaluated. Seeds were grouped into 3 classes each on weight (< 0.8 g, 0.8 - 1g and >1g classes) and size (diameter) (<12mm, 12-13mm and >13mm classes). The seedlings were allowed to grow and various parameters were collected for survival and growth studies. After a period of 6 months final growth parameters as well as above and below ground biomass were measured. It was found that seed germination, seedling survival rate, growth and biomass accumulation were better in seeds with weight >1g seeds among the seed weight classes; and in 12-13 mm seeds among the seed size (diameter) classes. Heavier seeds confer an advantage to their seedlings for survival and growth due to the presence of large reserve of nutritive substances. Better performance of medium size seeds probably constitutes an evolutionary trade-off between dispersal and establishment capabilities that is adaptive for most plants. Therefore, for large scale plantation of P. timoriana, heavier (>1g) and medium size (12-13 mm) seeds should be selected for better survival and growth.