An analysis of cotton remains from Huaca Prieta on the north Peruvian coast, dating from circa 2500 B.C. to circa 750 B.C., indicates that they were probably primitive forms of G. barbadense L. and similar in most features to those previously examined from sites in the Ancon area of the central coast (Stephens and Moseley 1974). As in the Ancon materials, there is a tendency for seed size, boll size and fiber width to increase from the earlier to later levels. Most of the Ancon materials belonged to the Preceramic Period, while at Huaca Prieta both Preceramic and Initial Periods are represented. Only fuzzy seeds were found among the Ancon materials and among the Preceramic materials recovered from Huaca Prieta. Tufted seeds first appear during the Initial Period at Huaca Prieta; it is the prevailing type among present-day cultivars, and may have been favored under human selection because their fibers are much more readily removed from the seeds by hand. It is believed that fuzzy seeds represent the more primitive condition; it is the prevailing type among present-day wild forms of G. barbadense. It remains a question whether the tufted seeds at Huaca Prieta originated as mutants in the locally cultivated fuzzy seeded types, or whether they were new forms, introduced along with pottery and other crop plants from elsewhere. None of the cotton materials so far examined from Peruvian coastal sites show affinities with cottons still extant in the Amazon Basin, and no wild, or apparently wild, forms of G. barbadense have yet been found east of the Andes.