Criminal organizations inhabit dynamic environments where the pressures of competition and state opposition constantly challenge their existence. To survive and prosper, they must be resilient. Little has been written about the concept of resilience in the context of illicit organizations. This article explores possible sources of resilience for criminal organizations, focusing on institutionalised gangs. Drawing on ecological and organizational literature, resilience is defined as the capacity to absorb and withstand disruption and to adapt to change when necessary. For gangs and other criminal organizations, sources of resilience may include environmental factors and individual organizational features such as network characteristics. Resilience is not just a concept that enables criminologists to better understand the longevity of some criminal organizations; it also has implications for the strategic and operational aspects of policing such organizations, including intelligence gathering, the design of interventions and assessment of their potential unintended consequences.