Left pectorobrachialgia, described here in 41 patients, is a frequent rheumatoid affection seen in general practice. It causes anterior chest pain with irradiation into the left arm, and patients often interpret it as being of coronary origin. The latter, however, is characterized by its different clinical presentation. Two forms can be distinguished: the typical form, which is an isolated entity, and the second, associated with and modified by fibromyalgia. It may coexist with angina pectoris and occur after myocardial infarction.