Length-weight relation of hake at first sexual maturity. This work was developed on the basis of 6,734 individuals of Merluccius hubbsi sampled. Estimations were made on individuals weighted to the hake population of the Argentine Sea south of 41° S. Length-weight relation potential regression parameters were a=0.00950863, 0.01093448 and 0.01096117; b=2.90831652, 2.86558431 and 2.86583191 for males, females and total individuals, respectively. The Newton algorithm was used to minimize the residuals. Maturity ogives were estimated with the logistic model adjusted by no lineal minimum quadratic ordinates. Length at first maturity at 50% was 33.79 cm for males and 35.38 cm for females. Age at first maturity estimated with the same model adjusted to the time elapsed from birthday to catching was 2.61 and 2.67 years for males and females, respectively. Good fitting in all regressions was obtained.