We herein report a case of gingival candidiasis in an advanced gastric cancer patient while receiving palliative cytotoxic chemotherapy. A 46-year-old male patient admitted to our hospital for known advanced gastric cancer with newly developed multiple liver metastases. While receiving 2nd line cytotoxic chemotherapy with 5FU, leucovorin, and paclitxel, he complained of gingival swelling accompanied by pain and whitish plaque. Due to lack of response to the conservative oral care, incisional biopsy of gingiva was done and the pathology confirmed gingival candidiasis. Although the lesion healed apparently after two-week antifungal therapy, pain as well as bony destruction remains. By presenting this case report, we intend to emphasize the immunocompromising effect of cancer while being on systemic chemotherapy.