This is an initial attempt to apply the principles of cognitive therapy to the treatment of adult offenders. The paper includes a brief presentation of the basic theory of cognitive therapy and a discussion of its relevance to criminal behaviour. It then describes a group of treatment techniques, with examples of their application. The interventions fall into three general categories: cognitive restructing and impulse control, problem-solving and social-skills training, and cognitive stimulation. Some of the techniques are borrowed, with adaptations. from the literature of cognitive therapy and some are presented here for the first time.