INTRODUCTION. The main goal of this work was to identify subgroups of patients with fibromyalgia (FM) by means of a frequently used clinical tool, the Fibromyalgia Impact Questionnaire (FIQ). METHODOLOGY. A total of 66 women diagnosed with FM participated in the study. Two subgroups of patients were identified by analysis of a hierarchical cluster of selected items from the FIQ (pain, fatigue, morning tiredness, stiffness, anxiety and depressive symptoms). RESULTS. The type I FM-group had very high levels of fatigue, morning tiredness and anxiety, and high levels of joint stiffness, pain and depressive symptoms, while the type II FM-group had predominantly moderate levels of fatigue and morning tiredness, with moderate low levels of pain and stiffness along with a low level of depression and anxiety. CONCLUSIONS. Type I FM-group also had lower healthrelated quality of life, especially through emotional reactions and social isolation as well as more psychopathological affections than presented by type II FM-group.