This is an exploratory-descriptive study about the comprehension of the effects of renal function and its relation to hipertension. The study was carried out with 12 members of a hipertension group (range from 18-60 years-old) entailed to a Basic Health Unit from a municipality of Rio Grande do Sul State. Data collection was carried out from March to May, 2004, by means of groupal interviews, approaching the focal technique. Analysis was proceeded according to thematic analysis and later categorization. Results demonstrated that the members, despite partially know renal physiopathology, they don't mean it as a consequence of high blood pressure.