Believes or the so called "old wives tales" on pregnancy are part of our cultural heritage, constituting myths that prevail in time. This study sought to explore whether myths can in fact be considered as aetiological factors in the nursing diagnoses made during pregnancy. A descriptive analysis was performed in pregnant women from two sociologically different population subsets: Lanzarote and Leon. Based on the results obtained, we were able to demonstrate that the population still has false believes, although these can be modified through heath education strategies.