The aim of the study was to compare the accumulation of β-adrenergic agonist residues clenbuterol (CLB) and salbutamol (SAL) in internal tissues, non-pigmented eyes and hair of laboratory animals repeatedly administered with CLB and SAL during 7 days. Experimental albino guinea pigs (n = 20) were treated with CLB (n = 10) and SAL (n = 10) in anabolic doses of 0.25 and 2.5 mg/kg, whereas the control animal group (n = 10) was left untreated. Methodology validation showed that the ELISA assay to be suitable for β-agonists' semiquantitative determination. The results revealed a significantly higher (P < 0.05) accumulation potential of CLB in comparison with SAL in all investigated tissues. Despite of their lack of pigmentation and the applied dose, the highest residual CLB concentrations were determined in the eyes of the studied animals, followed by their hair, liver, lungs, kidney, heart and adipose and muscle tissue, whereas residual SAL concentrations found in the eyes and hair of the administered animals did not significantly differ (P > 0.05) from those obtained in their internal tissues.