This research deals with the effects of exogenous growth regulators on leaf osmotic potential of tomato cultivar "Angela". To study the influence of growth substances on osmotic potentia, (2-chloroethyl) trimethylammonium chloride (CCC) at concentration of 2,000 ppm, succinic acid-2,2-dirnethylhydrazide (Alar) (3,000 ppm), and potassium gibberellate (Gibrel) (100 ppm) were applied. The leaf osmotic potential established everyday during six days showed that plants treated with Gibrel presented lower (negative) osmotic potential. CCC promoted better equilibrium in the osmotic potential of tomato plants. Leaves of tomato cultivar "Angela" presented higher osmotic potential in the morning in relation to leaves collected in the afternoon.