Diving can lead to the decompensation of pre-existing pathologies. But it can also lead to specific accidents, whether immediate or long-term. The medical monitoring of divers is based on a preventive approach based on the strict application of specific medical surveillance.In this book, we attempt to analyse the current situation regarding the conditions under which a medical certificate of fitness to dive is issued in Tunisia, and to clarify the practical arrangements for issuing it, between reality and legislation.