The population of Chilean edible sea urchin Loxechinus albus (Molina 1782) at Punta Lagunillas presents an annual bimodal reproductive cycle, with two periods of gonadal maturity. The first and principal maturity peak occurs in June, with spawning between the end of July and the end of August. This spawning season coincides with a surface water temperature of 14-degrees-C, the shortest daylength of the year and is immediately previous to the spring peak of primary production in northern Chile. The second summer maturity does not end with spawning, being the gametes produced in January, reabsorbed the end of February. The knowledge gained in this research made possible, together with the published information about the reproduction of this specie, to describe a generalized model of the occurence of the spawning season for populations of L. albus along the coast of Chile from Antofagasta (23-degrees-S) in the north, to the Guaitecas Islands (45-degrees-S) in the south.