Present paper deals with the occurrence and distribution of Hylocereus undatus (Haw.) Britton & Rose of the family Cactaceae is a species of botanical interest. Nearly 20 species of Hylocereus are recognized, and species of this genus distributed in Southern Mexico, Central America, West Indies, and Northern South America. One of the species, Hylocerus undatus, is growing naturally as an epiphyte on Pterocarpus santalinus Linn. f. (Rathhandun) in the Botany Department, Andhra University, Visakhapatnam, (Andhra Pradesh, India). Several investigators studied the floristic composition of Andhra Pradesh; but, so far there was no report was available in the literature regarding its presence in Andhra Pradesh.