Acquired copper deficiency has recently been recognized as a cause of myeloneuropathy mimicking subacute combined degeneration due to vitamin B-12 deficiency. A remote history of gastric surgery is frequently associated with this syndrome. However, the very limited prevalence of severe copper deficiency in patients with a history of gastric surgery suggests that additional contributing factors are likely to be involved. We describe a patient with copper deficiency and a previous Billroth II partial gastrectomy for gastric carcinoma, presenting with severe myelo-optico-neuropathy, demyelinating lesions of the brain, and subjective hyposmia. An abnormal glucose breath test also revealed small bowel bacterial overgrowth syndrome. Copper replacement therapy associated with antibiotic therapy was effective in preventing further neurological damage and in obtaining mild improvement. We propose that copper status should be evaluated in all patients presenting with unexplained noninflammatory myeloneuropathy. Small bowel bacterial overgrowth syndrome should be investigated as a cause of generalized malabsorption and a possible contributing factor to copper deficiency after gastric surgery, as should occult zinc ingestion.