In this study, the effects of tilmicosin on some haematological and biochemical variables were investigated. Ten male New Zealand rabbits were used as material. The tilmicosin was injected (25 mg/kg body weight, subcutaneously as a single injection), and the rabbits were monitored for 4 days. No negative effects of tilmicosin on haematological and biochemical variables were observed, but it did cause a temporary decrease in red and white blood cell counts.