Background: Patients with cancer are at risk for malnutrition and the development of anorexia-cachexia syndrome, which is often under-treated. The objective of our study was to determine the frequency of these conditions in advanced cancer patients who were evaluated in an outpatient Supportive Care Clinic (SCC). Methods: Advanced cancer patients seen in SCC were prospectively enrolled to complete a cross-sectional one-time survey. We collected patient demographics, weight history and height, cancer history, the Functional Assessment of Anorexia Therapy – Anorexia/Cachexia Subscale (FAACT-A/CS) questionnaire, Edmonton Symptom Assessment Scale (ESAS), the Patient Generated Subjective Global Assessment – short form (PG-SGA SF), and a Body Image Scale (BIS) questionnaire. Malnutrition was indicated by a PG-SGA cut-off of ≥ 5, and loss of appetite, anorexia, was defined as either ESAS ≥ 3 or FAACT-ACS ≤ 37. Results: Of 165 cancer patients that were approached, 100 (61%) completed the prospective survey. The average (SD) age was 61.6 years old (11.5). The majority of patients were female gender (52%), Caucasian (75%), were married (80%), and the most common cancers were gastrointestinal (22%) and genitourinary (21%). At the time of the survey, 14% of patients were noted to have a BMI < 20, 60% of patients reported anorexia (ESAS ≥ 3), 53% patients screened positive for the FAACT-A/CS (≤ 37), 69% were malnourished (PGSGA ≥ 5), and 55% had body image dissatisfaction (BIS ≥ 4). Documented weight loss of >10% in the medical records was recorded in 59% of patients with an average (SD) of -12.8% (15.3). Patient self-reported weight loss of > 5% over 6 months and > 10% over a lifetime was noted in 56% and 62% of the patients, respectively. Conclusions: Advanced cancer patients seen in an outpatient SCC are at high risk of malnutrition and roughly 60% experience complications of anorexia-cachexia syndrome. Routine screening for malnutrition and weight loss should be incorporated into all Supportive Care encounters, and nutritional counseling and support should be offered to the majority of cancer patients.