The influence of seed treatment with low-power laser radiation on some physiological parameters and yield of tomato hybrid HA3019 protected cultivation conditions. The seeds were irradiated with a laser He-Ne 25 mW power at different exposure periods 5,10, 20, 30 and 60 seconds, using untreated seeds as controls. We evaluated the germination percentage (%), survival (%), plant height (mm), root length (mm), stem diameter (mm), polar average diameter (mm) ecuatorial mean diameter (mm), mean fruit mass (g) and yield per plant (kg.plant-1). The results showed a significant increase (p?0.05) in the indicators of plants height (50%), root length (13%), stem diameter (17%), equatorial mean diameter (7%), mean fruit mass (13%) and yield per plant (67%), compared to control. This confirms the stimulating effect of low power laser radiation on growth and yield of plants.