Candidiasis of the gastrointestinal tract typically occurs in a setting of decreased re- sistance to opportunistic infection, but also occurs in apparently normal individuals. Mucosal lesions in the gastrointestinal tract predominantly involve the esophagus, and gastroduodenal and enteric candidial lesions, which are less frequent, have only infrequently been detected antemortem. A case was experienced involving esophageal and gastroduodenal candidiasis in the patient of hepatocellular carcinoma and spinal metastasis treated with emergent radiotherapy and corticosteroid. He complained of anorexia and dyaphagia in the 4th day of radiotherapy. Endoscopy revealed multiple, large raised, white plaques and patches covering the mid- and distal esophageal mucosa, and several superficial aphthous ulcerations covered with white plaques in the entire stomach, and two deep excavating ulcers at the angle and antrum. The duodenal mucosa was covered with multiple small, white plaques, and a huge penetraing ulcer was seen in the duodenal bulb. Endoscopic biopsy showed budding yeast and pseudohyphae infiltrating through the ulcerated mucosa. Cultures of the same material canfirmed the organism to be Candida albicans. The patient was treated with fluconazole for 2 weeks. The case of esophgeal and gastroduodenal candidiasis is reported with reviiew of relevant literature. (Korean J Gastrointest Endosc 18: 884-888, 1998)