The current study assessed the relationship between national religious affiliation and lethal violence by simultaneously examining homicide and suicide rates. The information on homicide and suicide rates for 124 countries came from the World Health Organization (WHO). Regression results suggested no significant difference in lethal violence between predominantly Catholic and Protestant countries, although Islamic countries revealed significantly lower homicide, suicide, and overall lethal violence rates than non-Islamic countries. Countries with a high level of religious heterogeneity are subject to an increased suicide rate. The implications of these findings were discussed.