Анотация: The aim of the present study was to investigate the effect of oestrus induction and timed artificial insemination on conception rates in Bulgarian Murrah buffaloes. Fifteen lactating non-primiparous buffaloes weighing 550-650 kg, fed and reared uniformly, were included in the survey. The animals were submitted to transrectal ultrasonography and divided into two groups depending on the ovarian follicle size: Group I (n=8) with follicle size <10 mm and group II (n=7) with follicle size >10 mm. The Ovsynch protocol for oestrus synchronization and programmed insemination was used. The clinical signs of oestrus (uterine tone, oestral discharges, cervical passage), conception rates and oestrus signs in non-fertilized animals were determined. The results showed that follicle size could be used as a criterion in selecting candidates for oestrus and ovulation synchronization in buffaloes from the studied breed. Oestrus-related discharges were observed in considerably higher number of animals from group II (71.4 percentage; p<0.05) as compared to group I (37.5 percentage). This oestrus synchronization and scheduled insemination protocols could be successfully used in Bulgarian Murrah buffaloes