We used both molecular and craniometrical data to test the presence of Hylomyscus walterverheyeni in the Cameroon Volcanic Line (CVL). Our molecular (cytochrome b and 16S gene sequencing) and morphometrical data (discriminant analyses) clearly show the presence of H. walterverheyeni in the CVL, north-west of the Sanaga River. Hylomyscus walterverheyeni occupies both lowland and mountain forests (up to 2000m asl). In our phylogenetic analyses, the CVL specimens form a monophyletic group. This clade seems to reflect the role of the Sanaga River as a barrier to gene flow within the species.