In order to contribute to the knowledge of beetles (Coleoptera) of the mountainous region of Morocco, Talassemtane National Park (Western Rif, Chefchaouen district, Morocco) was surveyed. This is an exceptional protected area of the Mediterranean Intercontinental Biosphere Reserve (RIBM). The checklist was made using different traps combined with active periodical searches during 2013–2015. A total of 153 beetles belonging to 19 species from four subfamilies (Cryptophagidae: Cryptophaginae and Atomariinae; Latridiidae: Latridiinae and Corticariinae) was collected. Dienerella (Cartoderema) talassemata, a new species (Coleoptera: Latridiidae) was compared to other morphologically related species. One species is recorded for the first time for North Africa; three species are new records for Morocco. In addition, amongst the species listed, three are endemic to Morocco: Dienerella talassemtana sp. n., Caenoscelis humifera and Dienerella besucheti.