To report two cases of abducens nerve palsy that occurred after the administration of chemotherapeutic agents.

( Case 1) A 49-year-old woman with breast cancer presented with acute onset of diplopia 6 weeks after the beginning of combination chemotherapy with cyclophosphamide, doxorubicin, and paclitaxel. She had a left esotropia of 30 prism diopters ( PD) with a mild decrease in abduction of the left eye. She was diagnosed with left abducens nerve palsy. ( Case 2) A 29 ‐ year ‐ old man with non-Hodgkin ’ s lymphoma presented with diplopia 7 weeks after beginning combination chemotherapy including cyclophosphamide, adriamycin, vincristine, and prednisolone. He had a 20PD esotropia in the primary position with a slight decrease in abduction of both eyes. He was diagnosed with bilateral abducens nerve palsy. The chemotherapy regimen of both patients was changed, and they were followed up without treatment. In case 1, diplopia improved 2 months after change of chemotherapy regimen with complete recovery within 4 months. In case 2, diplopia improved 2 months after a change of chemotherapy regimen with complete recovery within 3 months.