Fibromyalgia (FM) is a clinical syndrome characterised by chronic widespread musculoskeletal pain, stiffness, and tenderness in addition to a variety of physical and mental symptoms such as fatigue, sleep disturbances, depression, anxiety, cognitive dysfunction, headaches, and digestive problems. FM can be associated with or coexist with other inflammatory rheumatic diseases such as rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, and spondyloarthritis. This phenomenon is called secondary FM. Although FM cannot be considered an autoimmune disease, it may in some cases be an early sign of an autoimmune disease. Therefore, clinicians should be cautious in these situations. This case series presents three patients diagnosed with axial spondyloarthritis coexisted with FM symptoms.