This chapter describes the rationale and therapeutic methods based on Beck’s cognitive therapy (CT). CT is a specific method of psychological therapy in the generic category of cognitive behavioral therapies (CBT). Cognitive therapy is a structured, problem-focused treatment that places cognition, or consciously accessible thoughts and beliefs, at its center. The chapter outlines a model of adjustment to life-threatening illness, describes cognitive and behavioral therapeutic techniques, and provides evidence of the effects of CBT on quality of life. CBT has a substantial evidence base with a range of psychological problems. Because it is brief, problem-focused, and collaborative it has potential as a useful tool and in a “first aid” form may be a useful method for non-mental healthcare professionals. There are encouraging signs from randomized controlled trials that it is effective in the cancer setting both for early and advanced disease.