Livestock systems are a large global asset contributing to food security and poverty alleviation, but livestock supply chains have major environmental impacts at global scale. The scientific literature on agroecology has not yet integrated livestock systems; only 5 percent of the indexed studies concerning agroecology deal with livestock. Following Dumont et al. (2013), we review five principles for integrating livestock systems within the agroecology debate: (i) adopting management practices that aim to improve animal health; (ii) decreasing the inputs needed for production; (iii) reducing emissions; (iv) enhancing diversity within animal production systems to strengthen their resilience; and (v) preserving biodiversity by adapting management practices. Through a number of case studies from different world regions, we show that the key features underpinning agroecological livestock systems are an increased use of biodiversity, the integration of crops and livestock within a diversified landscape and a recoupling of the major element cycles. For intensive landless systems, we discuss how recycling principles derived from industrial ecology could complement those from agroecology. We conclude that performance criteria far beyond annual productivity are required when assessing agroecological livestock systems.