A 36-year-old man with a remote history of Hodgkin lymphoma and a recent history of non-Hodgkin lymphoma (NHL) developed tonic pupils and absent deep tendon reflexes in the lower extremities. One year later, pupils were normal except for slight iris segmental contraction to light. Over the next 2 years, the patient remained asymptomatic, and pupils remained unchanged. The NHL went into remission, and no other neurologic manifestations appeared. This is the first report of reversible tonic pupils. They may have a pathogenesis different from that typically seen in irreversible tonic pupils.