ABSTRACT This research's main goal is the description of the embryonic developmental stages of Gambusia puncticulata. It also provides an analysis of the embryonic mean developmental stage, and mean weight in relation to the mother's carcass weight. The fish were caught monthly from July 2006 to June 2007 throughout Almendares River, North of Havana, Cuba. The embryonic mean stage values (F4,600 = 14.79, P < 0.001), and mean weight values (F4,395 = 7.09, P < 0.001), increased with mother's size increment. This research describes, for the first time, seven embryonic developmental stages in G. puncticulata. The applied macroscopic classification of the embryos showed great consistency, due to the large number of examined specimens. The criteria used to define the stages are accurate, and allow to distinguish the stages easily, quickly and with high reliability. These criteria could be applied to other species of the Gambusia genus.