Rock fall hazard zoning and the appropriate design of rock fall protection measures constitute the main solutions to the problem of mitigating rock fall hazards. Nevertheless, the integration of the effects of protection measures into hazard zoning maps still remains an open question, as the correct operation of the protections during their whole life span might be overlooked. In this context, this paper presents a methodology for a simple yet effective evaluation of the effectiveness of rock fall protections, in order to provide assistance in deciding how to take them into account in hazard zoning and, possibly, how to reclassify hazard zones to a lower hazard level, according to the role played by the protections. The methodology consists of four main steps, from the data acquisition on the state of the protections to a two-stage evaluation of their actual effectiveness, to the possible reclassification of rock fall hazard according to the new hazard levels obtained in presence of protection measures. The methodology was developed based on the Swiss Codes for rock fall hazard zoning; however, despite its details and a simple application are shown in accordance to these guidelines, the approach presented is flexible, independent of national guidelines and therefore easily adaptable to any risk management framework.