The Ayacucho Archaeological-Botanical project was designed to locate evidence for the development of agriculture in the highlands of Peru. The first season of the project located a large number of stratified sites which, upon excavation, are expected to give a very complete sequence, not only for the region but for each ecological zone within the region. The most important excavation conducted during the first year was at Pikimachay Cave, which had been found previously. The earliest complex at Pikimachay, Ayacucho, consists primarily of unifacial tools, denticulates, and pebble tools, and appears to have no other counterparts in South America. These artifacts are associated with remains of extinct fauna, from one of which a radiocarbon date of 12,200 B. C. was obtained. An open site, called Puente, yielded a long sequence spanning the Jaywa and Piki complexes (the latter yielded at date of 4210 B.C.). The Puente complex, best represented at Jaywamachay Cave, has associated dates of around 6400 B.C. Analysis of the combined collections yielded a tentative artifact chronology spannng the early preceramic through Late Horizon times. The preceramic complexes are described and illustrated. The cultural climax in the region evidently occurred during the Middle Horizon, about 500-1000 A.D. Floral and faunal remains excavated during the project remain to be studied.