Pima cotton (Gossypium barbadence) requires close attention to harvest management to maintain the high fiber quality. Also, pima responds to harvest aid chemicals differently from upland cotton. Defoliation studies in far west Texas show phosphate defoliants (Def^® and Folex) caused little defoliation even at high rates. Ethephon (Preps) at 1 and 2 pounds a.i./acre caused rapid defoliation of mature leaves, and desiccation of immature plant parts. Ethephon treatments significantly improved boll opening and first pick over other treatments and the UTC. Thidiazuron (Dropp^®), endothall (Accelerate^®), paraquat (Cyclone^®) and sodium chlorate caused some defoliation, but did not significantly improve boll opening. Fiber quality was reduced by ethephon on the second picking since only a small portion of the crop, made up of immature bolls, remained. Low rates of ethephon produced the best combination of boll opening and defoliation.