This is an analysis of the legal nature of crimes of abstract danger, which have been used in great profusion by the Brazilian legislature in recent times. These types of offence seek to protect diffuse legal assets, a circumstance that would, in theory, require preventive action by the Criminal Law. In this sense, crimes of abstract danger aim to prevent damage to the legal asset by presuming - abstractly or concretely - the danger. In view of this, their constitutionality is discussed, especially in relation to the constitutional principle of offensiveness, by analysing doctrine and case law.