This study dealt with the population dynamics of the rabbitfish Siganus canal iculat us. one of the economically important fish o( the Arabian Gulf fisheries in Saudi Arabia. The length ;u recruitment (Lr) was 15 cm (total length for both sexes), its calculated weight about 57 g. and the corresponding age at recruitment (tr) was estimated from Von Bertalanffy equation as O.Sfi year for both sexes. The length at first capture (Lc) was 20.0. 21.0. and 20.5 cm for males, females and combined sexes, respectively. Converting these lengths (Lc) to age at first capture (tc) gave t^ about 1.57, 1.66 and L60 years for males, females and combined sexes. respectively. Generally, females of & canaUculams had larger size and heavier body weights than males. The monthly absolute condition factor (Kc) and relative condition factor (Ku) of S. canaliculaius was studied. The maximum age of S, canaliculaws was found to be five years in western Arabian Gulf at Saudi Arabia. The young fishes that belong to ages 1-2 years constituted about 60.72, 56.50 % and 58.52 %. while older fishes that belong to ages 3-5 years constituted about 39.28. 43.50 and 41.48 % for males. females and combined sexes, respectively. The computed total mortality coefficients (Z) were 1.48, 1.53 and 1.50 per year and the total mortality rates (A) of 77. 78 and 78 % with survival rates of 23. 22 and 22 % for adult males, females and combined sexes in the fish population. The natural mortality coefficients (M) of S. canaliculatus were found to be 0.73. 0.76 and 0.75 per year for males, females and combined sexes, respectively. The fishing mortality coefficients (F) reached 0.75. 0.77 and 0.75 per year for males, females and combined sexes, respectively. The exploitation ratio was discussed in order to help fisheries management in the Arabian Gulf.