Disocactus salvadorensis Cerén, Menjívar & S. Arias is described and illustrated. This new Cactaceae species grows in the northwestern department of Santa Ana, in El Salvador. It is a member of subgenus Disocactus and is distinguished by its tubular and pendulous flowers with yellow or pink, less often white, tepals that are erect but recurved in the distal one third, and by its stamens in two distant whorls. Within Disocactus Lindl. subg. Disocactus, this new species is morphologically most similar to D. eichlamii (Weing.) Britton & Rose and D. quezaltecus (Standl. & Steyerm.) Kimnach. Distribution and ecological information about the new species are provided.