The aim of the present study was to determine the effectiveness of artificial insemination in Buffalo at Coastal Region during October, 2018 to November, 2020 under Promoting Agricultural Commercialization and Enterprises (PACE) Project. A total of 176 cyclic buffaloes for artificial insemination and 594 cyclic buffalo for natural service were included in this study. The animals were inseminated artificially under four different times, i.e. inseminated i) between 6-12 hours after showing first sign of estrous, ii) between 13-18 hours after showing first sign of estrous, iii) between 19-24 hours after seeing first sign of estrous and iv) between 25-36 hours after showing first sign of estrous. The pregnancies (positive or negative) were confirmed by rectal palpation after 60 days of artificial insemination (AI). In case of Artificial insemination the pregnant animals were 29.55% and in case of natural service pregnant animals were 61.28%. The highest pregnancy rate (47.73%) was observed in insemination between 19-24 hours after seeing first sign of estrous and the lowest pregnancy rate (15.91%) was observed in insemination between 25-36 hours after seeing first sign of estrous. In case of artificial insemination calf mortality was lower (3.85%) than that of natural services. The birth weight of calf was higher in case of Artificial insemination than natural services. The findings of the study suggest that, with the expansion of AI programs in buffalo it was envisioned that the technique used in cattle required modifications in order to achieve the best results in buffalo at Coastal region of Bangladesh.