A morphology-based cladistic analysis was conducted of the coastal rove-beetle subgenera Emplenota Casey and Triochara Bernhauer of the genus Aleochara Gravenhorst. We used 36 adult characters from the all ten Emplenota and three Triochara species, and two outgroups, resulting in a single tree. The topology within the Emplenota clade shows a clear pattern of species diversification that correlates well with the biogeographical distribution of this taxon. The Emplenota clade was phylogenetically divided into three, consisting of a Nearctic clade forming a sister group relationship with the Eastern Palearctic clade, and a basal Western Palearctic evolutionary grade. In contrast, the geographical origin of Triochara remains unclear due to a paucity of information and difficulties in interpreting the distributional data.