Tylosin, a drug mainly used in veterinary medicine, belongs to the macrolide group of antibiotics. In this study the bioequivalence and differences in pharmacokinetics of solution and powdered tylosin formulations were established. The following recommended by EMEA parameters: Cmax, Tmax, AUC were determined. All the investigations were carried out in the populations of 74 broilers chickens. The concentration of tylosin in plasma was determined by means of the appropriately modified HPLC method. The mean maximum concentration (Cmax) of tylosin in plasma was found to occur 3.0 h (for powder and liquid) after oral administration. They were 403.20 ng/ml and 403.12 ng/ml respectively. The plasma profiles of tylosin following administration of both formulations were similar.