Zilpaterol hydrochloride (ZH) is a β-adrenergic agonist was approved in México (2002) and the United States (2006) to promote growth and carcass dressing in beef cattle. Forty Dorper × Katahdin (45.4 ± 4.5 kg) crossbred male lambs were used in a 27-d feeding trial (5 pens/treatment) to evaluate the influence of method of zilpaterol supplementation on growth performance and carcass characteristics. Lambs were fed twice daily with a cracked corn based (64%) experimental diet (1.39 Mcal/kg of NE_g and 14.0% CP). The animals were allotted to individual pens (6 m²) with full shade and ad libitum water. Treatments were (1) control (CON), no zilpaterol supplementation; (2) total dose of zilpaterol was offered only in morning feeding (AM), (3) total dose of zilpaterol was offered in morning and afternoon feeding (PPM), and (4) total dose of zilpaterol consisted in offering one day and suspended the next day, like intermittent supplementation (INT). Zilpaterol was supplemented at a rate of 0.20 mg/kg of live weight d−¹ (as zilpaterol chlorhydrate, Zilmax). The lambs were slaughtered in a local slaughterhouse. The data were analized at complete randomized design, with orthogonal contrast and means compare with LSD. Zilpaterol supplementation (CON vs AM, PPM) decreased the redness index (a*) (10.9%; P < 0.04), yellowness index (b*) (15.5%; P < 0.03) and chromaticity (13.6%; P < 0.02). Shear force values of zilpaterol supplementation tended to be greater (P = 0.08) than shear force values of CON. There were not differences on pH values between treatments. Zilpaterol intermittent supplementation (CON vs INT) reduced luminosity (L*) (10.3%; P = 0.05), no statistical difference was found with the remaining variables (P ≥ 0.12), similarly, the contrast (INT vs. AM) showed no significant differences (P ≥ 0.33) in all variables evaluated.