Patients undergoing cancer treatment often rely on the use of oral nutritional supplements (ONS) to maintain adequate calorie and protein intake to prevent weight loss. Despite the variety available, it can be challenging to find a supplement that patients are willing to consume on a regular basis. Taste acuity and preference can be affected by the cancer process, nutrition-related side effects of treatment modalities, and other factors. A single blinded palatability test of ONS was conducted with 40 radiotherapy outpatients representing various treatment fields (Head and Neck, Breast, Lung, Mantle, Upper Gastrointestinal Tract, Lower Gastrointestinal Tract, Pelvic, and Prostate). Ensure, Nutren 1.0, Resource, and Newtrition were included by meeting the following criteria: oral liquid; nutritionally complete; lactose-free; 1.0-1.4 calories/ml; caloric distribution: 13–15.9% protein, 45–56% carbohydrate, no more than 37% fat; provides 100% USRDA for vitamins and minerals in 2000 calories or less; assorted flavors; 8 oz. container. To reduce result bias, ONS were offered in random order and both vanilla and chocolate were sampled. Queries about diagnosis, treatment modalities, treatment week, previous supplement usage, nutrition-related therapy side-effects, smoking habits, packaging preference, and food aversions were obtained via questionnaire. ONS were evaluated for appearance, odor, flavor, and overall acceptability. Results showed the study group to be equally distributed in terms of sex, age, and cancer site. Most were in their 2nd to 4th week of treatment. Three were receiving chemotherapy or antibiotics in addition to radiotherapy. Participants reporting side effects were as follows: taste changes (8), nausea (6), diarrhea (4), vomiting (3), and sore mouth (2). Forty percent expressed a packaging preference for a can, 20% a carton, and 40% either one. None of the factors screened for had a statistically significant effect on overall ONS acceptability. ONS ranked from least to most acceptable overall in the following order: Nutren 1.0, Resource, Ensure, and Newtrition, with a statistically significant difference between Nutren 1.0 and Newtrition, but none between other supplements. Overall acceptability was most closely correlated with flavor score. Results of this study and a previous inpatient palatability study of 1.5 calorie/ml formulas will be incorporated into the Enteral Formulary selection process that occurs every two years at our institution.