In 1999, the massive die-off of the American lobster (Homarus americanus) populations in western Long Island Sound (LIS) caused complete collapse of the commercial lobster fishery. Reestablishment of a commercial fishery in western LIS requires, in part, knowledge of lobster populations that provide larvae to western LIS. To address this issue, larvae collected from sites within LIS were assigned to egg-bearing female lobsters by comparison of microsatellite allele frequencies. Egg-bearing female lobsters were collected from three sites within LIS and from a site in the Hudson Canyon (Crivello et al. 2005). Tissue samples were collected from female lobsters in spring, summer, and fall of 2001, and lobster larvae were collected in late summer of 2001 and 2002 from five sites within LIS. Differences in microsatellite allele frequencies were used to assign larvae to female lobster populations by a Bayesian and neural network approach. Larval assignments indicated that a high percentage (35% to 45%) of the larvae collected in the eastern or central LIS originated in female lobsters collected in the Hudson Canyon. In contrast, very few larvae collected in western LIS originated from females in western LIS (<30%) and the overall contribution of western female lobsters to the collected larvae was very low. The relative contribution of all sampled female lobsters to collected larvae was greatest from the Hudson Canyon area (35%), followed by central LIS (25%), eastern LIS (20%), western LIS (13%) and the Stratford Shoals area (7%). These results are discussed in context of reestablishment of a lobster commercial fishery in western LIS.