OBJECTIVE: There is a growing interest in injury as a public health issue across the world. There is paucity of data on the prevalence and social correlates of non-fatal interpersonal violence in low- and middle-income income nations. The objective of this study was to estimate the prevalence of, and associated factors for physical fighting among school-going adolescents in Santiago, Chile. METHOD: We conducted a secondary analysis of the Chilean Global School-Based Health Survey conducted in 2004 in Santiago. We aimed to assess the prevalence and social correlates of having been involved in a physical fight in the prior 12 months. RESULTS: Of the 2111 respondents, 40.7% (54.3% males and 26.6% females) reported having been in a physical fight in the prior 12 months. Males were more likely to have been in a physical fight than females [OR = 3.89, 95% CI (3.11, 4.85)]. Substance use (cigarette smoking, drinking alcohol, and using drugs) and bullying victimization were positively associated with fighting [OR = 3.05, 95% CI (2.40, 3.87) for substance use, and OR = 1.65, 95% CI (1.32, 2.05) for bullying]. Parental supervision was negatively associated with physical fighting [OR = 0.62, 95% CI (0.50, 0.78)]. CONCLUSION: We have estimated the prevalence of having engaged in a physical fight among in-school adolescents in Santiago, Chile. We have found that the prevalence is similar to what has been reported in diverse settings in Africa, Europe and North America.