Objective. Advanced cancer patients frequently experience debilitating symptoms that occur in clusters, but few pharmacological studies have targeted symptom clusters. Our objective was to examine the effects of dexamethasone on symptom clusters in patients with advanced cancer. Methods. We reviewed the data from a previous randomized clinical trial to determine the effects of dexamethasone on cancer symptoms. Symptom clusters were identified according to baseline symptoms by using principal component analysis. Correlations and change in the severity of symptom clusters were analyzed after study treatment. Results. A total of 114 participants were included in this study. Three clusters were identified: fatigue/anorexia-cachexia/ depression (FAD), sleep/anxiety/drowsiness (SAD), and pain/dyspnea (PD). Changes in severity of FAD and PD significantly correlated over time (at baseline, day 8, and day 15). The FAD cluster was associated with significant improvement in severity at day 8 and day 15, whereas no significant change was observed with the SAD cluster or PD cluster after dexamethasone treatment. Conclusion. The results of this preliminary study suggest significant correlation over time and improvement in the FAD cluster at day 8 and day 15 after treatment with dexamethasone. These findings suggest that fatigue, anorexia-cachexia, and depression may share a common pathophysiologic basis. Further studies are needed to investigate this cluster and target anti-inflammatory therapies. The Oncologist 2016; 21:384-390Implications for Practice: Results of this preliminary study suggest that fatigue-anorexia/cachexia/depression cluster scores significantly improved in the dexamethasone treatment group as compared with placebo.These findings indicate that symptoms in the fatigue/anorexia-cachexia/depression cluster might share a common causative mechanism. Further studies are needed to validate these findings.