The paper analyses the implementation of the portfolio over four academic years (2006-2010) in a sample of 480 nursing students. It was carried out in three phases (initiation, development, and consolidation), and its aims were: 1) to evaluate the effectiveness of the portfolio through a quantitative study with an ex post facto design, and 2) to analyze the strengths and weaknesses of the portfolio implementation process through a qualitative study using topic-based focus groups. The results indicate: 1) in the initiation phase, the average score of students who created the portfolio (7.78) is higher than the average score of those who did not do so (5.47) (p <= .001), and in the development and consolidation phases, the portfolio score and the subject grade come increasingly closer; and 2) the final portfolio design is characterized by being mixed (manual and electronic), modular, and self-reflective -empowering students in the learning continuum.