The Mordellidae of the Maritime provinces of Canada is surveyed. Thirty species have now been recorded from the region. Of these, 17 are newly recorded for Nova Scotia, 11 are newly recorded for Prince Edward Island, and 7 are newly recorded for New Brunswick, for a total of 35 new provincial records. Three species, Mordellistena indistincta Smith, Mordellistena rubrifascia Liljeblad, and Mordellistena rubrilabris Helmuth, are newly recorded for Canada, while a further 11 species, Mordella melaena Germar, Mordellistena aspersa (Melsheimer), Mordellistena errans Fall, Mordellistena morula LeConte, Mordellistena picilabris Helmuth, Mordellistena sericans Fall, Mordellistena vilis (LeConte), Mordellina ancilla (LeConte), Mordellina nigricans (Melsheimer), Mordellina pustulata (Melsheimer), and Glipostenoda ambusta (LeConte), are newly recorded for Atlantic Canada. One subspecies, Mordella atrata lecontei Csiki, is removed from the region's faunal listing. The composition of the region's fauna as a whole, and related biogeographic questions, are briefly discussed. The Mordellidae are also discussed in the context of forest beetle communities in the region and the impact of historical forest management practices on old-growth specialist species.