Rove beetle assemblages from forest dominated by yellow birch (Betula alleghaniensis Britt. (Betulaceae)) at two sites in southeastern Quebec were characterized in terms of composition, diversity, and relative abundance. In total, 143 species were collected over two seasons (June–August of 1999 and 2000). In the pretreatment year (1999), 88 species were found in uncut stands. In the post-treatment year, 116 species were found in treated (by patch harvesting and ground scarification) and control plots combined. Sixty-one species were common to the two sites, 27 species captured in the 1999 season were not recaptured in the 2000 season, and 55 additional species were captured in 2000. There are 23 new distribution records for Quebec, and one species, Atheta (Dimetrota) pseudomodesta Klimaszewski, sp. nov., is described. New bionomics data on relative abundance, seasonality, and the utility of different trapping methods are presented. Assemblage composition is compared with that of a red spruce (Picea rubens Sarg. (Pinaceae)) forest in New Brunswick.