Objective: To determine the effect of myofascial release techniques on pain symptoms, postural stability and physical function in fibromyalgia syndrome. Design: A randomized, placebo-controlled trial was undertaken. Subjects: Eighty-six patients with fibromyalgia syndrome were randomly assigned to an experimental group and a placebo group. Interventions: Patients received treatments for 20 weeks. The experimental group underwent 10 myofascial release modalities and the placebo group received sham short-wave and ultrasound electrotherapy. Main measures: Outcome variables were number of tender points, pain, postural stability, physical function, clinical severity and global clinical assessment of improvement. Outcome measures were assessed before and immediately after, at six months and one year after the last session of the corresponding intervention. Results: After 20 weeks of myofascial therapy, the experimental group showed a significant improvement (P < 0.05) in painful tender points, McGill Pain Score (20.6 +/- 6.3, P < 0.032), physical function (56.10 +/- 17.3, P < 0.029), and clinical severity (5.08 +/- 1.03, P < 0.039). At six months post intervention, the experimental group had a significantly lower mean number of painful points, pain score (8.25 +/- 1.13, P < 0.048), physical function (58.60 +/- 6.30, P < 0.049) and clinical severity (5.28 +/- 0.97, P < 0.043). At one year post intervention, the only significant improvements were in painful points at second left rib and left gluteal muscle, affective dimension, number of days feeling good and clinical severity. Conclusion: The results suggest that myofascial release techniques can be a complementary therapy for pain symptoms, physical function and clinical severity but do not improve postural stability in patients with fibromyalgia syndrome.