Objectives: Idiopathic inflammatory myopathies (IIM) are a group of inflammatory muscle diseases with a paucity of data and literature from Saudi Arabia. The aim was to describe the demographics, evaluate clinical features, organ involvement, investigations, treatment strategies, and to assess factors affecting remission in IIM patients. Methods:We conducted this retrospective study at 5 medical tertiary centers in Saudi Arabia to analyze the records of patients with IIM from 1999 to 2014.Results: A total of 28 patients with IIM were identified with a female to male ratio of 3:1. Pure polymyositis accounted for (32.1%), pure dermatomyositis (21.4%), juvenile dermatomyositis (10.7%), and IIM mixed with connective tissue diseases (35.7%) of the patients. The most common presentation was proximal myopathy (93.9%). The musculoskeletal system was the most commonly involved (78.6%), followed by the gastrointestinal system (39.3%). Investigations revealed an elevated CK of 2995.12 ± 3431.51 (mean ± SD), EMG was positive in (92.9%) of patient, and muscle biopsy in (42.9%). Treatment data showed a good response to Prednisolone (96.4%). Conclusion:The results of this multiregional retrospective study from Saudi Arabia on IIM patients showed similar clinical features to other reviews; however, malignancy percentages were lower. We found a strong relation between comorbid illnesses and relapse. Normalization of muscle power is a reliable prognostic factor that may help assess the efficacy of treatment.