The pattern of brood production was analyzed in the grass shrimpPalaemonetes pugio.Determination of patterns of brood production as successive (spawning after each molt) or alternate (spawning after every other molt) was made by observations on individual females paired with males in the laboratory over a four-month period. A pattern of successive parturial (spawning) molts was the most common pattern. However, in a majority of these successive parturials, the ovary of the female was not mature at hatching of embryos from a previous brood. There was a delay of 10–11 days, during which ovarian maturation took place, between embryo hatching and the next (parturial) molt. This pattern of “slow successive” parturials does not result in the truly continuous brood production which occurs in many caridean species, i.e., spawning of a new brood within 1–2 days after hatching of a previous brood. However, there was a relatively low percentage of females in which the ovary was mature at embryo hatching. These latter females did have a parturial molt after only 2 days (“fast successive” parturial). In the “alternate” pattern, more frequent later in the 4-month observation period, hatching of embryos was followed by a non-parturial (without spawning) molt within 2 days, followed by an intermolt period of 10 days during which ovarian maturation occurred prior to the next (parturial) molt. The interval between spawns was similar in the “slow successive” and “alternate” parturial molt patterns (22–23 days) compared to a much shorter one (14–15 days) in the “fast successive” parturials. Examination of reproductive females from field samples indicated that the spawning pattern observed in the laboratory was that which occurs in natural populations in southern Louisiana. Although brood production inP. pugiois not truly continuous, the relatively short interspawn intervals observed still allow production of several broods during the breeding season.