The incidence of psychological distress-depression, anxiety, delirium-in patients with cancer ranges from 35% to 50%. Demoralization, a new concept, has not been included in most studies. The role of the oncologist in managing depression, anxiety, and demoralization involves diagnosing the problem, providing verbal support, first-line psychotropic medications, and referral to the psycho-oncology team. Empirical studies have shown that oncologists have difficulties in recognizing psychological stress and talking with patients about it. Reasons include a belief that distress is "normal"; the subject matter is embarrassing and uncomfortable; they feel unskilled; and time constraints. Therefore, the role of communication training in medical school and for oncologists in training is important. Screening for psychological distress may identify patients; however, inadequate psychosocial follow up and support may make screening counterproductive. Depression and anxiety constitute most psychological distress and will be described in formal psychiatric terms (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) and subjective descriptions. Demoralization, a concept recently introduced to psycho-oncology, is reviewed. Demoralization acts as a bridge from traditional psychiatric terminology to newer concepts used to describe the particular psychological distress characteristic of advanced cancer. Word concepts, such as meaning, spiritual, dignity, and existential, capture the patients' distress that is not defined by formal psychiatric taxonomy. Management modalities for depression, anxiety, and demoralization are discussed.