Abstract During the last decades, there has been an increasing interest in the analysis of a potentially dangerous phenomenon for the public health: pseudoscience. It can be defined as the set of false knowledge that attempts to resemble science even though it is not. Nowadays there are many who opt for these therapies not scientifically endorsed to solve their health problems. This situation is increased for risk patients or chronic diseases, who come to this type of therapies as a last resort. In these cases, the choice between science and pseudoscience can become a matter of life or death. Through qualitative and quantitative research techniques, we analyze the reasons why patients choose pseudoscience instead of conventional and scientific medicine. The data obtained from this research reveal that in extreme situations patients value most the human contact with the therapist that the validity of the therapy itself. This factor, coupled with the precariousness of the health system, generates a dynamic in which pseudosciences gain ground over scientific medicine. According to the experts interviewed, this phenomenon is increasing and may represent a danger to public health. This research reveals the possible causes and consequences of this phenomenon from the point of view of more than 60 professionals of the Spanish scientific community and 30 patients who have used both disciplines. The results obtained indicate that this situation is intensified due to the inaction of the competent institutions and the lack of regulation.