Numerous investigations show that most school science teaching, in Spain and elsewhere, implicitly transmits an inductivist and very stereotyped view of science and conveys an unrealistic image of scientific work. We present some results of an investigation with fourth-level Spanish secondary education students (15 year olds) who were taught genetics through a unit based on an open problem-solving methodology as an investigation. Among the learning objectives were the modification of their view of the nature of science in relation to ideas about: how science is done, what a theory is, what scientists do, and, finally, what the relationship is between Science-Technology-Society. The conceptual change about the nature of science experienced by the students in the experimental group was not observed in the control group, which worked in a traditional manner. Also, these new concepts remained with the students over time without a significant backward shift. (Contains 5 tables.)