Background: Job stress and burnout are highly frequent in healthcare professionals, and prevalence in nurses can be as high as 40%. Mindfulness-based interventions have been shown to be effective in reducing stress and increasing well-being in a wide range of populations and contexts. However, controlled studies with healthcare professionals, and especially nurses, are scarce. Objectives, design and setting: The aim of this study was to explore the effectiveness of an on-site, abbreviated mindfulness-based intervention for nurses, using a nonrandomized, wait-list comparison design. The effectiveness of the intervention was measured through several validated self-report measures that participants completed before and after the intervention, assessing burnout, compassion fatigue, psychological symptoms, mindfulness, self-compassion, experiential avoidances, rumination, and satisfaction with life. Participants: A sample of 94 oncology nurses agreed to participate in the study and self-selected into an experimental (n=45) and comparison condition (n=48). Complete data was obtained for 48 of the initial 94 participants, mainly due to poor follow-up data rather than high drop-out rate. Results: Statistical analyses included a series of 2 x 2 ANOVAs and ANCOVAs. Results indicated that nurses in the intervention reported significant decreases in compassion fatigue, burnout, stress, experiential avoidance, and increases in satisfaction with life, mindfulness and self-compassion, with medium to large effect sizes. Nurses in the comparison group didn't present significant changes in these variables. Results also pointed to a high degree of acceptability of the intervention. Conclusions: This study provides preliminary evidence that mindfulness-based interventions may be efficacious in reducing oncology nurses' psychological symptoms and improving their overall well-being, and thus may be worthy of further study in this population. (C) 2016 Elsevier Ltd. All rights reserved.