Introduction. The article focuses on examining the problem of constitutional and legal content of the presumption of innocence in doctrinal, legislative and law enforcement aspects. On the basis of the analysis of the practice of the Constitutional Court of the Russian Federation the author makes a few conclusions and generalisations concerning the implementation of the constitutional principle of presumption of innocence in the Russian public law. The presumption of innocence has nothing in common with the legislator’s desire to exempt really guilty persons from legal liability If the guilt is properly proved, a person cannot avoid punishment even if refusing to testify against him/herself and does not plead guilty. But the guilt must be proved in a proper legal procedure: the use of improper evidence, prejudice due to a defendant’s keeping silent (avoiding answering the question about confessing guilt) or denial of guilt – these are the circumstances that Article 49 of the Constitution of the Russian Federation directly protects against. Interpretation of the constitutionally guaranteed presumption of innocence in the opposite regard would represent a defect in legal consciousness to be overcome. Methods. The author applied a set of methods developed and tested by constitutional and legal science, history of the state and law. The methods of analysis and synthesis, induction and deduction, dialectical approach, method of comparative jurisprudence were particularly involved. Results. The author proves that the main content (core) of the presumption of innocence lies in its three fundamental components: fair distribution of the burden of proof; establishment of guilt by a competent authority and at the appropriate stage of the law enforcement process; respect for proper legal procedure in proving facts and identifying legally relevant circumstances. When analysing the constitutional and legal content of the presumption of innocence, the issue of compliance of the actual practice of criminal prosecution, defence of the accused and criminal punishment with the natural law and common sense of specific corpus delicti of criminal offences is actualised.