Abstract: Background and Objective: The BCS is one of the main factors affecting the reproduction of cows influencing postpartum interval (PPI), conception rate (CR) and calving interval (CI) in the beef cow. The purpose of this study was to conduct a performance evaluation on body condition score (BCS) of beef cattle raised under natural pasture conditions. The evaluation was objectively to observe the reproductive performance of cows influenced by low BCS. Materials and Methods: Body condition score (BCS) of 113 beef cattle in a herd structure of (n = 12 heifer calves, n = 7 bull calves, n = 8 weaner heifers, n = 13 weaner bulls, n = 4 steers, n = 5 heifers 5, n = 63 cows and n = 1 bull for natural service) were assessed using 9-point BCS scale. The BSC assessment was conducted during the 5 months from May to September, 2020. Only three observations were done on BCS of the individual animal (tagged) respective to the normal PNGUNRE beef cattle farm husbandry practices. Weaning rate, conception rate and calf survival rate were calculated to evaluate the assessed BCS of the cattle herd. Results: Breeding cows are affected by a low BCS of 4 with obvious indications of very poor reproductive efficiency indicated by increased postpartum interval (PPI) and calving days. Low quality pasture has affected reproduction efficiency in the current herd structure. Conclusion: Moderate BCS of 4 has affected the reproductive performance of beef cattle production at PNGUNRE. Genetic improvement using either selection tool within the breed or introducing crossbreeding programs to diversify breeds, AI programs, pasture improvement, supplementary feeding, feedlot system and correcting the bull to cow ratio of 1:63 for the current herd are immediate considerations to improve performance in beef cattle production.