Abstract: The experiments were conducted aiming to evaluate the effect of three estrus synchronization protocols viz. Ovsynch, CIDR and CO-Synch+CIDR on LH Peak, Plasma P4 and follicular dynamics in a fixedtime AI (FTAI) in locally adopted non-descript indigenous cows. The blood samples were collected at 2 h intervals, starting at 12-108 h from post PGF2α to determine the LH surge and for P4 on day 0, 4, 7, 11 and then once weekly for 8 weeks of estrus synchronization and FTAI. A better synchrononyof LH peak was observed in Ovsynch group (48.40±0.40 h post PGF2α) compared to CIDR (71.67±9.74 h) and CO-Synch+CIDR (54.86±4.71 h) protocols. The mean follicular diameter, daily growth rate and ovulation rate did not differ (p>0.05) among three groups. The interval between PGF2α and ovulation was lower (p>0.05) in Ovsynch group when compared to CIDR and CO-Synch+CIDR groups. The conception rate at first service (80%) in Ovsynch group was significantly higher (p<0.05) compared to CIDR and CO-Synch+CIDR groups. It is concluded that the time of LH peak in synchronized estrus of non-descript indigenous cows is simsilar to taht in Bos Tauruscows and Ovsynch protocol induced the best synchrony of pre-ovulatory LH surge and ovulation.