Abstract: In this study, relationships between width/length-weight and width-length by sex and combine were estimated 1133 individuals belonging to 8 species from 5 families in the North-eastern Mediterranean coast of Turkey. Regression coefficient between the regression of W-CL, W-CW and CL-CW for female, male and both were found very high (p<0.001) and the median value of b W-CL were 3.135, 3.132 and 3.081; W-CW were 3.135, 3.132 and 3.081, respectively. The r2 values ranged from 0.91-0.99.