The current study aimed to evaluate the effects of carp pituitary extract (CPE) and ovaprim (OVA), administered separately or in combination, on sperm quality parameters, fry mortality after hatching, blood sex hormones, and blood biochemical parameters of grass carp (Ctenopharyngodon idella). A total of 81 fish were divided into three treatment groups, each comprising 27 fish (18 females and 9 males; average weight 7200 ± 30g). The treatments were as follows: intramuscular injection of OVA at 0.5ml/ kg body weight (T1), CPE at 4mg/ kg body weight (T2), and a mixture of OVA and CPE (T3). The results demonstrated a highly significant increase in male testosterone and in the levels of blood hormones (FSH and LH) across treatments after four weeks of injection in both sexes. Furthermore, significant elevations in total bilirubin, direct bilirubin, and indirect bilirubin were observed in both female and male fish in all treated groups compared with their corresponding controls. Semen characteristics—including total density, relative density (%), motility duration, motility percentage, milt volume, and pH—were also evaluated. Results indicated improved sperm quality overall. The T1 group (OVA) exhibited significantly higher values in all reproductive performance parameters compared to the other groups, while the T3 group (OVA + CPE) showed the lowest values (P< 0.05). However, no significant differences were detected in milt pH among the three treatments (P> 0.05). In conclusion, OVA treatment enhanced sperm viability and reproductive performance in male grass carp (Ctenopharyngodon idella).