Fibromyalgia is characterized by widespread pain and tenderness; however, comorbid cognitive difficulties are a common complaint among patients. Known as fibro fog or dyscognition, this symptom comprises difficulties with complex cognitive processes including memory, executive function, concentration and attention. While the mechanisms that initiate and maintain these cognitive deficits are still largely unknown, recent research has increased the understanding of subjective symptoms and objectively-determined deficits in cognitive performance. Treatments have also improved to include complementary cognitive and physical strategies. This review focuses on issues of dyscognition in fibromyalgia. Details of objective testing methods are not within the scope of this paper.