The objectives of this study are to describe appropriateness and drug treatment of comorbidities in fibromyalgia (FM). Cross-sectional study of a group of patients. Number of drugs, indication, duration and appropriateness of prescriptions were evaluated. Patients were classified as: group 1, (FM/FM) previous FM diagnosis and fulfilling criteria; group 2, (noFM/noFM) other diagnosis and not fulfilling criteria; and group 3, (noFM/FM) other diagnosis but fulfilling criteria. Drugs were classified into drugs for nervous system, analgesics/NSAID and drugs for other comorbidities. Appropriateness was evaluated following clinical therapeutic guidelines. A total of 159 patients were included in the study and classified into group 1, with 59 patients; group 2, with 67 patients; and group 3, with 33 patients. Group 1 received a greater number of different drugs and for a longer period of time, there were less severe comorbidities and more unjustified treatments. No difference was found between the other two groups. Major opioids were only consumed in group 1. Also, in group 1, 45.8 % of patients were attended in psychiatry versus 15.6 % in group 3 and 3 % in group 2. The number of somatic symptoms correlated significantly with the number of drugs. Nervous system treatments were of shorter duration than other drug treatments. There was no difference in severe comorbidities. Comorbidities in FM are similar to those of other patients, but they receive more drugs and for a longer period of time. Drugs for nervous system comorbidities are introduced later, when other somatic symptoms are already treated. In patients with FM the treatments for mild comorbidities are not well justified.