The need for legal certainty is the essence of the law. Criminal labour law in Chad and Cameroon is part of this logic. It is an intermediary discipline between criminal law and labour law, which emerged in the 19th century at a time when the social order required additional protection. Its purpose is therefore to support social regulation by prescribing prohibited conduct and, where appropriate, the penalties to be incurred in the event of transgression.The originality of this work is that it deals with what happens to criminal law when it infiltrates the social world, in other words labour law. Labour law has proved to be a special case, from incrimination through procedure to repression.