Leptomeningeal metastasis(LM)is a rare complication in patients with breast cancer. We report 3 cases of LMs in patients with breast cancer who were treated with intrathecal methotrexate via an Ommaya reservoir. In 2 patients, a significant neurological improvement was observed, whereas in 1 patient there was no response. The overall survivals for the patients who experienced improvements were 22 and 9 months. Although we have no evidence for the efficacy of intrathecal chemotherapy for LMs in patients with breast cancer, its effects for some patients could be promising, after reservoir management and drug selection establishment.