Because school violence is widespread, social and emotional competence must be targeted. Second Step is a social and emotional violence-prevention curriculum that teaches prosocial skills and reduces aggressive behavior. The purpose of this study was to examine the effects of Second Step implementation on students (N = 403) in preschool through fourth grade who were predominately Latino, English language learners, and from families with low socioeconomic status. The data of 165 out of the 403 students were included in the present study. Analyses consisted of paired-samples t-tests to identify changes in social and emotional knowledge and behavioral and emotional risk. Results showed that there was a significant increase in both social and emotional knowledge and behavioral and emotional risk following the implementation of Second Step. These results are discussed with regard to previous and future research, limitations, and implications for school practice.