This article is generically dedicated to the legal effects of the acts practiced by young people, both minors and those of legal age, under the influence of drugs. In Part I, our attention is called to the legal-civil consequences of these acts. Thus, we shall begin with a brief preliminary note on the concept of civil law. Having noted this, we will examine the main topic to speak of the legally existing mechanisms (within the scope of civil law) to protect those people, and for this purpose, we distinguish between minors and adults (or equated to adults, which is the case of minors who are emancipated by marriage): the minor regime, in the firstcase, and possibly, the regime of incapacitation (an incapacity that is not generic and permanent), or even accidental incapacity (not permanent or transitory), caused by the consumption of alcohol or drugs, in the case of adulthood (or equated with adulthood). In the second part, initially, we give a general presentation of criminal law, with this part divided into two large sections: the sale and consumption of narcotics and the legal treatment given to minors. From a general standpoint, when an analysis of the agent’s guilt cannot be made, the law considers him to be unimputable. From an internal standpoint, we shall analyze the most relevant legal aspects of the Decree-Law referring to traffic and to drugs. One particular aspect of this regime lies in the fact that in Macau, drug consumption is considered to be a crime (article 28), unlike in European countries, like Portugal, since 2000. We shall also take into account other legislation in Macau in which drugs play a crucial role, as is the case of the misdemeanor established in article 68 of the Highway Code, which consists, among other items, in driving under the influence of alcohol or narcotics (note that this Code was recently altered by the Highway Traffic Law, which entered into effect in October 2007). Next, we will analyze the regime applied to minors from a concrete perspective of criminal law.