Purpose of review <p>The recognition of autoimmune and paraneoplastic antibodies in neurological disease has expanded substantially in recent years. Acquired nystagmus may serve as an early or presenting manifestation, particularly in rapidly progressive syndromes. We review a practical approach to the evaluation of patients presenting with new-onset nystagmus or abnormal saccadic oscillations. </p> Recent findings <p>Distinct nystagmus phenotypes have been linked to specific antibody-mediated syndromes, while in others considerable overlap exists. Opsoclonus is increasingly recognized as a nonspecific finding across multiple etiologies. Additionally, the acute vestibular syndrome may represent an early manifestation of antibody-mediated disease (e.g., GQ1b, KLHL11). When an autoantibody etiology is suspected, early empiric immunotherapy and a thorough evaluation for underlying malignancy are warranted. </p> Summary <p>In this article review, we summarize the types of acquired nystagmus, outline a comprehensive workup and initial treatment approach for suspected autoimmune or paraneoplastic etiologies, and we discuss how the nystagmus semiology may inform localization, guide evaluation, and prioritize targeted antibody testing. </p>