Trends in behaviour therapy are considered from the advent of cognitive behaviour modification to the more recently suggested emphases on affective and unconscious processes. The thrust towards integrating different schools of psychotherapy is also briefly reviewed. The gains and losses associated with the trends are discussed. Some suggestions for the future are offered with respect to potentially profitable directions for behaviourally orientated researchers, practitioners and teachers to follow. A general theme of the paper is that behaviour therapy appears to be fractionating at an accelerating rate, and whilst this carries the potential for some very significant advances, it also carries the potential for destroying the unique contribution of the behavioural approach.