This study assessed the ability of the Symptom Checklist-Revised (SCL-90-R) to discriminate between two groups of fibromyalgia patients (those who were about to begin a treatment including the explicit aim of returning to work and those who were initiating a legal procedure to obtain permanent disability compensation) and two groups of healthy volunteers (medical students and psychology graduates), who were asked to produce a symptomatic resemblance to a chronic pain disorder. Logistic regression analyses were applied to the SCL-90-R subscales and individual probabilistic indices of simulation were calculated. Results showed that the SCL-90-R was able to discriminate between healthy subjects and both groups of patients with a high sensitivity and specificity. The individual indices of simulation, which might be more useful in clinical practice than the comparison of the SCL-90-R profiles, also showed an appropriate level of accuracy.