Annonaceae is a diverse pantropical plant family with 113 genera and about 2550 species. Cameroon is one of the most biodiverse countries in Africa but its flora remains incompletely known. The Flore du Cameroun, Volume 45: Annonaceae is the first volume to be co-published by the Ministère de la Recherche Scientifique et de l’Innovation (MINRESI, Yaoundé Cameroon), The National Herbarium of Cameroon and PhytoKeys (Pensoft Publishers). In this volume of the Flore du Cameroun, the authors describe 166 native taxa representing 163 species in 28 native genera within the family. A total of 22 species (about 13%) are endemic to the country. Dichotomous keys to all genera, species, and infraspecific taxa are provided. For each species, a detailed morphological description and a map of its distribution in Cameroon are provided. Line drawings and/or photographs accompany most species. Distribution maps and diversity analyses are based on a taxonomically verified database of 2073 collections. Across Africa, Cameroon is a centre of diversity for Annonaceae harbouring one of the highest numbers of species and genera.