Syndrome of inappropriate antidiuretic hormone secretion (SIADH) has various causes including central nervous system disorders, pulmonary and endocrine diseases, paraneoplastic syndromes, and use of certain drugs. SIADH induced by chemotherapy with irinotecan-cisplatin is not a common complication. Here, we review a case of SIADH after treatment with irinotecan-cisplatin. A 45-year-old woman received adjuvant chemotherapy (paclitaxel-carboplatin) for ovarian clear cell carcinoma, but the cancer recurred within 9 months of chemotherapy. Subsequently, a second line of combination chemotherapy containing irinotecan-cisplatin was initiated. However, 5 days after chemotherapy administration, her general condition began to deteriorate; her hematological tests revealed hyponatremia. Therefore, it is imperative to consider the possibility of SIADH in patients being treated with irinotecan-cisplatin-based chemotherapy. Proper monitoring of serum sodium levels and assessment of clinical symptoms should be performed in such patients for early diagnosis and prompt management.