Chloroquine and hydroxychloroquine (HCQ) are commonly prescribed antimalarial agents used for a variety of systemic diseases. HCQ neuromyotoxicity is a rare complication characterized by proximal muscle weakness, normal creatinine kinase levels, and characteristic ultrastructural changes on muscle biopsy of curvilinear body formation. In this report, we describe a patient with rheumatoid arthritis and respiratory failure associated with proximal myopathy secondary to HCQ. Characteristic changes on muscle biopsy were present. Patients treated with HCQ in whom proximal myopathy, neuropathy, or cardiomyopathy develop should be evaluated for possible HCQ toxicity. Clinicians should be aware of this unusual complication of antimalarials, as discontinuation of the agent may result in clinical improvement.