There is no clear-cut consensus or reliable body of published data in the Andean literature indicating whether llamas were bred and herded on the prehistoric North Coast of Peru or periodically imported from the highlands. Based on four lines of evidence—ethnographic, archaeozoological, physiological, and ethnohistoric—we argue that llamas (and perhaps even alpacas) were successfully bred and maintained on the North Coast from the early Middle Horizon (ca. A.D. 600) and perhaps since the Early Horizon. More specifically, we discuss population structure, representation of body parts, climatic and dietary adaptability, and abundance of coastal forage. Both llamas and alpacas are physiologically well-adapted for the coastal environment and can efficiently process a wide range of forage. By the Middle Horizon, domestic camelids served a wide range of functions including transport, sacrifice, tools, and meat. Species identification, coastal herd management, effects of disease vectors, and other related issues are also discussed.