Fifteen buffalo heifers of similar age and weight investigated during mid-luteal phase. Ten superovulated with pFSH (65 NIH units, Super-Ov, divided into 6 equal doses, injected for 3 consecutive days) and 25 mg Lutalyse given with fifth injection. LH (2000 USP unit) injected 12 hour (h) from treatment. Rest 5 heifers kept as control. Blood samples taken before treatment (0h) then after 12, 24, 48, 72, 96, 120 and 144 h. Sera collected and kept at –20 C° for estrogen (e) and progesterone (p) determinations using Enzyme Immunometric Analyzer. Superovulated heifers slaughtered after last blood samples to count corpora lutea (CL) and unovulated follicles (UF). Oviducts and uterus flushed to recover embryos. Results classified into high response group (HRG) > 2 CL (3.8 ± 0.49) and low response group (LRG) < 3 CL (1.2 ± 0.2). Nine embryos recovered from HRG where significant increase in e noticed at 72 h followed by marked decrease. The increased e in LRG continued till last sample with significant difference (P < 0.05). The total number of UF was significantly lower (P<0.05) in HRG. The overall p levels (ng/ml) were significantly lower (P<0.01) in HRG than LRG and control. Lutalyse induced significant reduction in p after 2 days from injection in HRG only. Wide variations in p levels (ng/ml) were noticed in buffalo heifers at the start of treatment, during mid luteal phase and low concentrations reported with HRG (0.87±0.33). Therefore, low levels of p at the beginning of superovulation could indicate successful ovulatory response.