This companion guide for clinicians working with oncology patients outlines clinical management of depression, demoralization and anxiety in a pragmatic format for use in everyday practice. The specific aim is to describe treatments that can be utilized by cancer clinicians and by mental health professionals training in psycho-oncology. The guide is not intended to replace national clinical guidelines and policies but gives a more generic international overview of the important factors and elements that need to be considered when dealing with clinical anxiety and depression in cancer patients at all points on the treatment trajectory. The guide covers assessment methods for clinical anxiety, demoralization and depression, psychopharmacological and psychological treatment methods, along with information on dealing with psychiatric emergencies and self-harm issues. The guide does not offer a comprehensive description of psychotherapy techniques: these can be found in the IPOS Handbook of Psychotherapy in Cancer Care. Policies, service issues, ethical, confidentiality, and communication issues are also covered. The guide is intended as a brief pocketbook manual that can be used for quick reference.