Outcome research is a new dimension of clinical research, and all fields of clinical medicine are involved in this kind of analysis. Overall survival and quality of life are the main outcomes identified in clinical oncology. The former must be the main outcome whenever possible; the latter has to be the main outcome when an improvement of overall survival cannot be expected. It follows that quality of life is the main outcome of palliative care, in which the patient instead of the disease represents the target of the clinical approach. In our critical paper, we review the meaning of clinical outcomes in palliative care, classifying the outcomes as main and surrogate outcomes, and the results of the trials as indexes of activity and efficacy of a treatment. We also review the main randomized clinical trials on the treatment of cancer cachexia, trying to define the role of the treatments in cachexia-related symptom control and quality of life improvement. Strictly related to outcome analysis is the dimension of pharmacoeconomic evaluation. The models of the different designs of pharmacoeconomic analysis are revisited in an attempt to conjugate the pharmacoeconomic evaluation with the particular dimension of palliative care.