Background: After treatment, patients with active cancer face a considerable burden from the effects of both the disease and its treatment. The Palliative Rehabilitation Program (PRP) is designed to ameliorate disease effects and to improve the patient’s functioning. The present study evaluated predictors of program completion and changes in functioning, symptoms, and well-being after the program. Methods: The program received referrals for 173 patients who had finished anticancer therapy. Of those 173 patients, 116 with advanced cancer were eligible and enrolled in the 8-week interprofessional PRP; 67 completed it. Measures of physical, nutritional, social, and psychological functioning were evaluated at entry to the program and at completion. Results: Participants experienced significant improvements in physical performance (p < 0.000), nutrition (p = 0.001), symptom severity (p = 0.005 to 0.001), symptom interference with functioning (p = 0.003 to 0.001), fatigue (p = 0.001), and physical endurance, mobility, and balance or function (p = 0.001 to 0.001). Reasons that participants did not complete the PRP were disease progression, geographic inaccessibility, being too well (program not challenging enough), death, and personal or unknown reasons. A normal level of C-reactive protein (<10 mg/L, p = 0.029) was a predictor of program completion. Conclusions: Patients living with advanced cancers who underwent the interprofessional PRP experienced significant improvement in functioning across several domains. Program completion can be predicted by a normal level of C-reactive protein.