The objective of this work was to study the effect of priming with water (H2O) and potassium nitrate (KNO3) solution with different concentrations (0,3M, 0,5M and 0,7M) and different soaking periods (zero, 24, 48 and 72 hours) on eggplant seeds performance. The priming was done in Erlemayers with 250ml of H2O or KNO3 solutions continual aerated at 20°C constant temperature. After priming seeds were dried until they reach the same initial moisture content. The seeds were evaluated by the following tests: germination test; germination at sub-optimal conditions; necessary time to maximum germination; modify cold test; radicle length; dry matter weight and seedling emergence. The priming is efficient in improve eggplant seed performance in laboratory tests. Priming eggplant seeds with KNO3 0,3M for soaking period of 48 hours show better performance in the germination, in the radicle length, in the biomass accumulation and in the emergence.