The presence of a lawyer in a criminal process is the most effective means of protecting the suspect (accused), since it is the defender who can provide qualified legal assistance. The problematic issues of the participation of a defense counsel in a criminal case have been studied for a long time. At the same time, the versatility of the topic under consideration objectively determines the fact that not all issues have been studied in an exhaustive way. In particular, certain aspects of inviting and appointing a defense lawyer, the procedural registration of the actions of the investigator to provide a defense counsel to the accused (suspect) continue to be controversial. The main purpose of the article is to resolve the problematic issues of the appointment and entry of a defense counsel into a criminal case. The procedure for the entry of this participant into the criminal process is complicated by a dual nature: in the procedural plan, the moment the defense attorney begins to participate is inextricably linked with the activities of the investigator (interrogating officer), and in organizational matters - with the decision of the legal community authorizing the lawyer to defend. In connection with the existence of two ways of the appearance of a defense counsel in a criminal case, the article presents a distinction between the essence of defense by agreement and by appointment. Topical issues of procedural registration of the status of a defender in criminal proceedings are also considered. The author proposes recommendations for improving the criminal procedural legislation in terms of regulating the procedure for the entry of a defense counsel and his activities in the framework of the criminal process, attempts are made to unify law enforcement practice on the procedural fixing of the moment the defense attorney begins to participate.