Spider mite, Tetranychus urticae (Koch), populations in three cotton varieties in 1966, and four in 1967 were measured under controlled and uncontrolled conditions and data on plant injury, mite abundance and yields were compared for each variety. The variety Pima S-2 (Gossypium barbadense) was affected very little by mites. Auburn 56 (G. hirsutum) was severely damaged in the absence of pesticidal controls. Acala 4-42 and Acala SJ-1 (G. hirsutum varieties) suffered an intermediate amount of damage and yield depression from an uncontrolled infestation of mites. Fiber quality was affected only in the Auburn 56 variety.