Many invasive species succeed in becoming established in new locations because of their competitive superiority to native species. This has been demonstrated in several examples involving mosquitoes. In this study, we examined the interspecific larval competition between a well established, though invasive, species, Culex pipiens, and its ecologically similar, native congener, Cx. restuans. In general, when differences were observed, we found lower interspecific competition relative to intraspecific competition for both species, suggesting that they do not compete strongly. However, these results were equivocal, with small observed differences in competitive ability. Nevertheless, previously observed seasonal patterns of activity suggests phenological avoidance of competition may be occurring, warranting further investigation of the interactions between these two species.