Since its discovery as the 6th plant hormone in 1970, Brassinosteroids (BR) has been use with several purposes including: stress tolerance, photosynthetic enhancement and yield improvements. This work shows the results of exogenous foliar spraying of BioUltra (BR´s) in two moments of lettuce plants development. Potted lettuce plants (Lactuca sativa L. cv. “Sargaso”) were sprayed twice using a BR´s solution [25 ppm or 250 mg ha-1] at 5 and 10 days after planting (DAP). Results show significatively higher number of leaves (19%), higher foliage fresh (36%) and dry weight (29%) on the treated plants relative to the control plants. This results demonstrate the feasibility of BioUltra for lettuce yield improvement.