In this paper, I approach the concept of legitimate interest as the classic devise of continental law to determine the legal standing of the plaintiff in the access to the administrative justice system. It is maintained that this concept has been introduced in the Chilean legal system, joining the concept of subjective right, as a legal position of a substantial natu-re. Legitimate interest is, therefore, at the base of environmental claims. It is argued that the legitimate interest is a requirement different from the proce-dural interest to bring a case before a Court of law. En el presente trabajo se aborda la figura del interés legítimo como posición jurídica legitimante clásica del contencioso administrativo de raíz continental. Se sostiene que esa figura existe en el derecho chileno, junto al derecho subjetivo, como posición jurídica de carácter sustancial de los administrados y está en la base del contencioso de reclamación ambiental. Requisito diferente es un interés procesal para recurrir.