Descriptions, illustrations and discussions of relationships are provided for two new taxa of Leptocereus (A. Berger) Britton and Rose collected from the karstic limestone cliffs and summits of two hill ranges in Pinar del Río province, western Cuba: Sierra de San Carlos and Sierra de La Güira. Both ranges are located within the pleated geographic domain of Cordillera de Guaniguanico, a complex geological structure that spans more than 150 km of the island. The description of these two novelties, Leptocereus assurgens var. nov. albellus from Sierra de San Carlos and Leptocereus chrysotyrius sp. nov. from Sierra de La Güira, brings the total number of taxa of Leptocereus known from Cuba to 13. A key for the seven species and the new variety of Leptocereus endemic to western Cuba is provided, along with pictures of their flowers.