Light-chain (AL) amyloidosis is the most common form of systemic amyloidosis and is associated with an underlying plasma cell dyscrasia. The disease often is difficult to recognize because of its broad range of manifestations and what often are vague symptoms. The clinical syndromes at presentation include nephrotic-range proteinuria with or without renal dysfunction, hepatomegaly, congestive heart failure, and autonomic or sensory neuropathy. Recent diagnostic and prognostic advances include the serum free light-chain assay, cardiac magnetic resonance imaging, and serologic cardiac biomarkers. Treatment strategies that have evolved during the past decade are prolonging survival and preserving organ function in patients with this disease. This review outlines approaches to diagnosis, assessment of disease severity, and treatment of AL amyloidosis.