Seed dispersers are important contributors to plant spatial associations and genetic structures. In this study, we examined the connections between seed dispersal and the spatial and genetic structures of a dominant neotropical palm Attalea phalerata. Field observation and genetic parentage analysis both indicated that the majority of A. phalerata seeds were dispersed locally over short distances (<30 m from the maternal trees). Spatial and genetic structures between adults and seedlings were consistent with localized and short-distance seed dispersal. Dispersed seedlings also exhibited strong spatial and genetic structures. These patterns are probably associated with the dispersal of seeds by rodents and the survival of recruits at specific microsites over time. Our cross-cohort analyses found palms in older cohorts and cohort pairs were associated with a lower proportion of offspring and sibling neighbours and exhibited weaker spatial and genetic structures. Such patterns are consistent with increased distance- and density-dependent mortality over time among palms dispersed near maternal palms or siblings. We conclude that dispersal activities are important in maintaining the positive spatial and genetic structure, and in contributing to distance- and density-dependent interactions among A. phalerata palms.