the aim was to evaluate the effectiveness of evidence implementation through participatory-action research (par). a prospective quasi-experimental design with two non-equivalent and non-concurrent groups (2006 and 2008) was adopted. the research was conducted at the bone marrow transplant unit of a tertiary-level spanish hospital. to put the evidence in practice, par was adopted as an "intervention studied". the dependent variables were: professional performance and patient outcomes (psycho-emotional area and adverse effects). in total, 125 patients were recruited (1st period=56; 2nd period=69). the results in the second period show significant improvements in professional performance in terms of the quality of the registers of signs and symptoms. in the psycho-emotional area, the psycho-social adjustment improved significantly; without caregiver burden or satisfaction showing any clear tendencies. among the adverse effects, catheter-related thrombosis and catheter-related infection improved significantly; there were no significant differences in the level of pain or mucositis. through the par, evidence could be put in practice and the outcomes under analysis could be improved.