Lowland Susiana, in the modern-day province of Khuzestan, southwestern Iran, was a major contributor to the cultural development of the ancient Near East. Thanks to more than a century of archaeological investigation, Susiana is also comparatively the best known region in the entire area. Excavations at numerous sites, but primarily at Susa and Chogha Mish (OIP 101), in Susiana provided a long sequence of archaeological phases that span some 8, 000 years, from early prehistoric times to the early Islamic period. The initial phases of the colonization of Susiana by early farmers, however, remained unknown until a series of excavations at Chogha Bonut pushed the earliest period of occupation of Susiana to the aceramic phase, ca. 7200 BC. The present publication presents and analyzes the results of three seasons of excavations at Chogha Bonut.