We present a taxonomic review and systematic revision of the Eyelash Palm-Pitviper Bothriechis schlegelii (Berthold, 1846) based on examination of 400 museum specimens, a phylogeographic analysis of 818 locality records, and 80 individuals sampled for molecular characters. We find morphological and phylogenetic support for five new species of Bothriechis Peters, 1859, which we describe here based on their unique combination of molecular, meristic, hemipenial, and color pattern characteristics. They are: B. klebbaisp. nov., B. rasikusumorumsp. nov., B. khwargisp. nov., B. rahimisp. nov., and B. hussainisp. nov. Finally, we revalidate the names B. nigroadspersus (Steindachner, 1870), B. nitidus (Günther, 1859), and B. torvus (Posada Arango, 1889a), and provide a redescription of B. schlegelii.