Introduction: Fibromyalgia (FM) is a chronic syndrome characterized by widespread musculoskeletal pain, sleep disturbances, asthenia, fatigue, and a set of cognitive symptoms named "fibro fog". The quality of life of FM patients is significantly lower than in other rheumatic diseases. The most recent studies confirm the crucial role of chronic stress (distress) both in the etiology and in the maintenance of the syndrome, aggravating the already compromised condition of central sensitization. Given the clinical complexity of FM, the treatment requires a multidimensional approach; in this regard, the scientific community has recently become interested in the contribution of contemplative practices and mindfulness, as regards the reduction of stress. The purpose of this study was to explore the effects of a Mindfulness-Based Stress Reduction intervention (MBSR) on FM patients. Method: Over a period of three years, four groups of women with FM (N=28) underwent an MBSR intervention, followed by psychological testing (pretest–posttest design), including: anxiety (SAS), perceived stress (PSS), mindfulness (MAAS), sleep quality (PSQI) and general well-being (PGWBI) measures. Given the sample size, t-test and other non-parametric tests were performed. Results: Overall, the findings showed a significant improvement after MBSR (PSS, SAS, PSQI, PGWBI <.05). Participants showed lower levels of stress and anxiety after the intervention, and an increasing of general wellbeing and sleep quality. Conclusions: The present pilot study confirmed the effectiveness of mindfulness-based interventions in reducing stress and improving sleep awareness and quality in FM patients. Future studies should include control groups while increasing the sample size.