<b><i>Background:</i></b> Respiratory impairment is a problem seen in people with multiple sclerosis (pwMS) from the early stages of the disease but not frequently recognized by clinicians until the later stages. It is seen in different ways, such as respiratory muscle weakness, change in pulmonary volumes, and decrease in cough efficiency. This situation has consequences affecting individuals’ physical fitness, participation in daily life, and quality of life. <b><i>Summary:</i></b> This review explains possible respiratory impairment mechanisms, related problems, assessment, and rehabilitation approaches in pwMS. <b><i>Key Messages:</i></b> It is recommended a comprehensive assessment of respiratory functions in pwMS regardless of the disease severity and stage. In addition, pulmonary rehabilitation and other exercises can have positive effects on the respiratory functions of pwMS. In future studies, specific training parameters should be determined for pwMS to achieve optimal benefits. There is also a need for studies that apply respiratory muscle training in pwMS who have a high disease severity and limited participation in the activities of daily living.