Background: The study of risk factors for antisocial and delinquent behavior has flourished in the past 20 years, as great strides have been made in understanding the developmental pathways that give rise to the onset, course, and desistance of the behavior. However, as a body of literature, risk factor research (RFR) is characterized by heterogeneity in definitions, conceptualization, and measurement of key constructs that can make it difficult to discern robust from spurious findings. This may pose challenges to child-serving agencies invested in developing crime reduction policies and programs but lack the resources to carefully comb through and make sense of the literature. Objective: This article reviews the terminological, conceptual, and methodological issues in the RFR literature with an aim towards clarifying some of the inconsistencies that limit interpretation and application of findings. Risk factors related to antisocial and delinquent behavior are used to illustrate the concepts discussed. Method: We reviewed the RFR literature pertaining to antisocial and delinquent behavior in children and youth to identify key concepts and discrepancies in this area. Conclusions: The literature would be well served if researchers were consistent in their use of terminology to describe the effects of risk factors on antisocial and delinquent behavior. There is also a need to study the processes and causal mechanisms that link past events to future outcomes.