A rapid increase in cancer incidence accompanied by aging population requires evidence-based supportive cancer care practices.Cancer therapies often accompany adverse events which induce malnutrition and declined quality of life. We conducted an 8-weeknon-randomized clinical trial to evaluate efficacy of cereal-based oral nutritional supplement (ONS) intervention on nutritional status,quality of life and inflammatory responses in cancer patients undergoing cancer therapy with 5% < weight loss. The study included34 pateints (24 in control group, 10 in intervention group) with 15 drop-outs. ONS used in this intervention contained 0.5% arabinoxylan-rich fermented rice bran powder and 5.5% black rice powder as active ingredients in a regular cereal-based formula. Resultsshowed that ONS intervention for 8 weeks did not show significant improvement in blood biomarkers of nutritional status or patient-generated subjective global assessment scores. However, 8-week of intervention showed reduced interleukin (IL)-6 and IL-1bsecretion in lipopolysaccharide-stimulated peripheral blood mononuclear cells while IL-12p70 level was increased. For health-relatedquality of life (HRQoL) indices, emotional functioning and fatigue symptoms were improved after 4 weeks only in the interventiongroup although no difference was found at week 8. These results suggest that ONS intervention may improve chronic inflammatorystatus and HRQoL indices (at week 4) in cancer patients receiving treatments.