Taste disorders are frequent occurrences among those patients under the FOLFOX-FOLFIRI regimen for colorectal cancer. We conducted a study on the development of taste disorders among colorectal cancer patients under this regimen and the effect of such disorders on their QOL. Taste disorders occurred in 58.1%(18/31 cases)of these patients and the disorders affected appetites in 50%(9 cases). The changes in taste sensations were subtle in most but some described certain tastes as exaggerated. Others reported changes in all taste sensations, including sweet, salty, bitter and sour, as well as deliciousness. When tested via the QOL Survey Sheet(Quality of Life Questionnaire for Cancer Patients Treated with Anticancer Drugs: QOL-ACD), the QOL was found to have deteriorated significantly in those who stated that taste disorders affected their appetite, in comparison with those who were unaffected. In patients with colorectal cancers and treated with the FOLFOX-FOLFIRI regimen, taste disorders are frequent occurrences. The poor nutritional state due to a loss of appetite may constitute a factor responsible for a lowering QOL.