The outcome of 34 women with anti-Yo-associated paraneoplastic cerebellar degeneration was reviewed. Three patients had not developed cancer after more than 4 years of follow-up. The only independent predictor for survival was the type of associated tumor (risk ratio, 1.79; 95% CI, 1.02 to 3.12). Median survival was 100 months for patients with breast cancer and 22 for those with gynecologic cancer. Although paraneoplastic cerebellar degeneration leads to the diagnosis of cancer in 63% of the patients, cancer progression was the cause of death in 52%.