Abstract: The present study was carried out to determine the bioequivalence of 2 different products of sulphaquinoxaline (SQ) used orally in broiler chickens. In the present study, 40 unmedicated 28 day-old chicks (Ross 308) were used. Animals were divided into 4 experimental groups, each containing 10 chicks. Sulphaquinoxaline at a level of 100 mg kg^-1 BW was given to Group I via intravenously and Group II, III and IV via the intracrop route. Blood samples were taken into sterilized tubes at 5, 15, 30 and 45 min and 1, 1.5, 2, 3, 4, 6, 9, 12, 18, 24 and 36 h following drug administration. Plasma SQ concentrations were measured by spectrophotometer (Schimadzu, UV1601). Both drugs were distributed according to a 2-compartment open model following their administration of intravenously. The sensitivity of the extraction method for SQ was detected as 1.41 �g mL ¹; the mean recovery value of the extraction procedure for SQ was detected as 90%. When compared the drugs of Group III (reference; A) and Group IV (test; B) for SQ bioequivalence; although mean AUC and C_max values decreased, an increase in mean t_max values was observed. Mean AUC and C_max values for SQ were found to be within acceptable ranges (80-125%) when compared with mean AUC and C_max values for A and B drugs. Data obtained in the present study showed that both drugs had similar bioequivalence. As a result it was concluded that both drugs could be substituted for each other as an inter-changeable drug.