Summary.The investigation was carried out in a comprehensive school from November to June of a school year with a class of 26 third‐year pupils of average ability. Behaviour modification techniques were used in an attempt to raise the pupils' performance in creative writing, using the variables fluency, elaboration and flexibility. Following a baseline phase in which the pupils' scores on the variables were neither rising nor falling, a procedure was implemented which involved points, appropriate levels of teacher comment and the promise of a letter to parents. The results showed considerable increases in the pupils' essay scores on the three variables. Six secondary school teachers of English judged a sample of the essays and the results of these judgments strongly suggest that the increased scores obtained do reflect increases in the pupils'performance in creative writin