Some courts have upheld school districts' decisions to discipline teachers for their behaviors outside of school if there was a connection back to the school. Specifically, many courts have adopted a nexus theory that suggests that a teacher's off-duty conduct might have a negative impact on his or her teaching effectiveness. Disciplinary action is more easily justified when incidents involve illegal activity, but an increasing number of teachers are being disciplined for entirely legal activity. This article concludes that school officials need to tread carefully when disciplining teachers for their out-of-school conduct. Although not every jurisdiction has adopted the nexus theory, it provides a helpful framework for school leaders to follow. If school officials can clearly demonstrate that a teacher's off-duty conduct has a negative impact on his or her teaching effectiveness, especially if the activity is illegal, it may be permissible to discipline the teacher.