A biometric study was carried out on 121 specimens of Portunus validus caught by fishermen in April 2022, in Loango Bay. The objective of this study is to determine the morphometric parameters of this crab species. The results obtained show that the sex ratio in favor of males is equal to 1.47. The total carapace length of the specimens varies between 24.42 and 66.4, with an average of 37.03±12.14. The total width of the carapace of the specimens varies from 21.62 to 175.6 mm with an average of 83.66 ± 23.53 mm while the weight varies between 1.8 and 362 g with an average of 46.80 ± 5.28g. There are variables presenting significant differences with the sex: length of the hand of the large and small cheliped (LM1, LM2), the distance between the external ends of the orbits (Le), the lengths of the merus of the pairs of pereiopods (LMP2, LMP3, LMP4 and LMP5), the widths of the merus of the second (lMP2), third (lMP3) and fifth (lMP5) pairs of pereiopods and the weight. The other variables do not present significant differences at the α=0.05 threshold. The size-height relationships show a diminishing allometry except for the inter-orbital distance; this allometry also differs between males and females. The weight-height relationships show a lowering allometry regardless of the group considered.