The objective of this study was to quantify the impact of standardized assessment and management tools on patient symptom scores in cancer-induced anorexia cachexia syndrome (ACS) using a within-group study design. Baseline assessments included the Patient Generated Subjective Global Assessment (PG-SGA) tool and an amended Symptoms and Concerns Checklist (SCC). Symptom management strategies, written for this project, were instigated. Follow-up SCC scores were collected at 2 and 4 weeks. Forty out of 79 patients referred were recruited; 29/79 (36.7%) were too unwell or had died prior to consent. At baseline, the PG-SGA tool revealed 250 active symptoms associated with ACS. Total PG-SGA score was above 9 for all patients. Predominant interventions involved simple dietary advice and prescription of artificial saliva, mouthwash and prokinetic antiemetics. Median total SCC score improved sequentially from 11 at baseline, to 7 and 4 at first and second review, respectively (visit 1 to 2, p = 0.001; visit 1 to 3, p < 0.001; and visit 2 to 3, p = 0.02). We conclude that patients with ACS are recognised late in their disease and have a considerable burden of active symptoms. A structured approach to assessment and management has a significant impact on symptom burden.