The implications of genetics and genomics for critical care nurses are becoming more evident, not only in the care provided but also in the numerous medications administered. Genetic causes are being discovered for an increasing number of chronic illnesses and diseases, such as Huntington disease. Because of the scientific and pharmacological advances, leading nursing organizations, such as the American Nurses Association, have established competencies in genetic knowledge for nurses. Such competencies help ensure quality care. Recent advances in the pharmacogenomics of therapy for human immunodeficiency virus disease, cancer, cardiovascular disease, and malignant hyperthermia have indicated a genetic linkage; therefore treatments are targeted toward the genetic aspect of the abnormality. Critical care nurses need knowledge of these genetic conditions and of medications affected by genetic factors.