Aglaonema costatum f. concolor is reported as a new record for the flora of Vietnam. The taxon was recently found in Phong Nha - Ke Bang National Park, Quang Binh Province. It is illustrated with detailed photographs of key morphological characters taken from the field. A key to all known taxa of Aglaonema in Vietnam is given. | Aglaonema costatum f. concolor Nicolson (araceae): A new record for the flora of Vietnam