A comparative study of feeding and host preference was made among immatures of Ixodes dammini Spielman, Clifford, Piesman & Corwin, I. scapularis Say, and I. pacificus Cooley & Kohls, using white laboratory mice, Eumeces lizards, and chickens (3-4 d old) as hosts. Larval feeding of each species when placed on hosts was greater (P less than 0.05) on mice than on chickens and lizards and higher on lizards than on chickens (P less than 0.05). When larvae of the three species were given a choice between mouse and lizard and mouse and chicken, they preferred mice (except no statistical difference was found between mice and chickens for I. pacificus larvae). When given a choice between lizard and chicken, no significant difference in host preference was seen. Nymphs of I. dammini, I. scapularis, and I. pacificus displayed no statistical difference in feeding ability between mice and lizards when placed on these hosts, but more ticks fed on mice and lizards than on chickens. Nymphs of all three species also showed no preference between mice and lizards but preferred either of these hosts to chickens (however, no statistical difference was found between mice and chickens for I. dammini nymphs or between lizards and chickens for I. pacificus nymphs).