The present study was developed to create methodological tools to understand the functional role of different psychological factors and their influence on health/disease, from the perspective of a specific theoretical model: the Psychological Model of Biological Health proposed by Ribes on 1990. Within this framework, an instrument was built for its use, in another moment, to evaluate the relationship between competences, that is, the capability of a person to face different environmental situations, and health/disease, taking into account affective and valuative dimensions of competences. Thus, this paper presents research related to the design and validation of an instrument designed to evaluate competences in three dimensions: effective, affective and valuative, such as some features of health/disease. The instrument was applied to 180 voluntary subjects. Once it was applied, different statistical analyses were made in order to validate it. The results show that the instrument is valid and reliable and therefore its application for different purposes is suggested.