The article aims to evaluate an eventual express regulation of the harm principle in the future Chilean Constitution. The article starts by examining the background, meaning and regulation of this principle. Then, it addresses its relationship with other principles that limit the ius puniendi, as well as the importance of its regulation as an autonomous principle. Likewise, the text refers to the harm principle as the basis of an adequate legislative technique in criminal matters. The article concludes that an explicit regulation of this principle in the new Chilean Constitution, through an immediate and clear formulation, would be a great step forward, among other things due to its character of limiting the action of both the legislator and the judge in the punitive field.