A study was conducted on the length-weight relationship and condition factor (k) of 6,254 fish samples representing 20 species belonging to 11 families of important marine fishes off Lagos coast, Nigeria. They were collected with a trawl net (cod-end 20mm mesh size), trawled at different depth ranging from 10m-100m between May and June 2009. The estimated 'b' value (regression coefficient) of the equation W = aLb ranged between 2.29 and 3.46 with mean and mode values of 2.78 ~c 0.28 and 2.79 respectively while the 'a' value (regression constant) ranged between -2.6019 and -0.9023 with mean value of -1.6899 ~c 0.40. The condition factor (k) ranged between 0.52 and 11.89 with mean values of 2.71 ~c 2.64. Fish species of Nigeria coastal water are dominated by Pseudotolithus senegalensis which is about 13.4% of the total fish samples and their growth trend is mostly isometric (exhibit dimensional equality of the body parameters). All the species studied are in good condition (k> 0.5)
