Saguenay Lac-Saint-Jean (SLSJ), a geographically isolated region located in northeastern Quebec, has an incidence of cystic fibrosis (CF) of 1 in 902 live births and a carrier rate of 1 in 15 inhabitants. Forty two families among those registered at the local chapters of the Canadian CF Foundation were randomly selected. A multiple-choice questionnaire was applied during an interview. It included 102 questions pertaining to the sociodemographic status of the participants, their knowledge of the disease and their reproductive attitudes. All the educational and socioeconomic levels were represented in the sample; 76% of the respondents were married. Before answering the questionnaire, 86% estimated their knowledge of the transmission of CF to be good or excellent; in fact, the rate of good answers to various questions ranged from 71 to 95%. The birth of a child with CF had a major impact on further pregnancy planning (a 69% reduction or arrest). Seventy one percent of the respondents used a more effective contraception method (including vasectomy and tubal ligation) after the birth of the CF child; in 63% of them, the decision was a direct consequence of the presence of the disease in the family. Thirty four respondents (81%) knew that prenatal diagnosis was available; 90% were in favor of such a prenatal test but only 17% would have required an abortion should the fetus be affected.