External supervision of teams is increasingly part of mechanisms put in place both in public networks and community organizations to contribute in supporting professional mental health workers in developing their abilities and improving their clinical practices. It also plays a role in the analysis of ethical questions and in the prevention of deontological errors. The supervision of teams also includes its share of challenges, notably with regards to group dynamics and mechanisms to favour in order for supervision to rightly adjust to the needs and levels of participating professionals. Finally, the supervisor must also consider his own ethical responsibilities towards those supervised and towards their clients.