Ukrain, thiophosphoric acid alkaloid derivative from Chelidonium majus L., was administered i.p. to ovariectomized rats in doses of 7, 14 and 28 mg/kg every other day for 10 days, followed by a 10-day break, and the procedure was performed five times. At the end of long-term treatment with Ukrain (24 h after the last dose of the drug) the rats' right femora were harvested and the bone densitometric parameters of the whole bone and distal metaphyseal and basicervical subregions were assessed using the dual-energy X-ray absorptiometry (DXA) densitometric method. The present results show a decrease in bone mineral density in groups of ovariectomized rats that received 7 mg/kg and 14 mg/kg of Ukrain versus untreated ovariectomized animals. Administration of Ukrain at a dose of 28 mg/kg did not significantly alter bone parameters of ovariectomized rats.