We describe a new species of Dixonius on the basis of five specimens from Phu Quy Island, Binh Thuan Province, in southern Vietnam. The new species can be distinguished from congeners based on molecular and morphological differences. Diagnostic features are: small size (SVL up to 44 mm); 7 or 8 supralabials; 11 or 12 rows of keeled tubercles on dorsum; 21-23 ventral scale rows; 5 or 6 precloacal pores in males; a canthal stripe running from rostrum through the eye and terminating behind the head; second pair of postmentals about one third to one half size of first pair; ground color of dorsum brown, with one or two rows of light yellow or orange spots in one or two rows along flanks, and irregular bands or a reticulated network of dark marks on dorsum. This is the fifth species of Dixonius known to occur in Vietnam.