A new method for the determination of clenbuterol by reversed-phase HPLC with UV detection has been developed. Clenbuterol was eluted on a C8 column (250 x 4.6 mm I.D), using an isocratic eluent consisting of an acetonitrile -0.02 M phosphate buffer (25:75, v/v) adjusted to pH 2.8 with phosphoric acid. The method was linear from 2.5 to 50 ng injected. The detection limit was established to be 0.5 ng (signal/background ratio: 3), and the quantification limit was 2.5 ng. With the proposed method, we got a simple and rapid detection of clenbuterol in the retina, part of the animal where the biggest amount of clenbuterol is accumulated and where it remains for the longest time after any treatment.