The provision o f Employee Assistance Programmes (EAPs) in this country has seen a rapid growth in recent years. However, there has been relatively little research into the effectiveness of such programmes in reducing costs of sickness/stress, absenteeism or in improving work place performance, particularly with respect to gender, age and professional status differences in responses to counselling. This research sought to evaluate the clinical change produced by a very specific mode o f counselling which was 'brief (up to a maximum of 8 sessions). The research also aimed to estimate the costs of stress to the organisation more accurately, by way of costing absenteeism and 'presenteeism' (the level of efficiency at which the employee estimates s/he is working). The first stage of this research was to find the baseline scores for the measures going to be used for the counselling sample. 'Well-being' questionnaires were randomly distributed to the 17,500 workforce (i.e. 5295 questionnaires were sent out). Over 2,300 responses were received. The results from this stage allowed for baseline mean scores to be obtained for all measures used. The responses focussed on the interaction between gender and other demographic variables such as age and professional status, and the effects of those interactions on the various means for stress factor and coping strategy responses. The second stage of the study examined the change process for clients coming for brief therapy as provided to them under an external EAP (241 subjects). The mean scores on a variety of scales at the pre-treatment stage were matched against responses at the post-treatment stage and again at a six month follow-up stage, and these scores were compared with the baseline means obtained for each factor from the earlier 'Well-being' study of the whole organisation. The process of matching looked at whether there were significant changes between the stages of the study and whether the changes produced clinically significant and reliable change. The effect size of that change was also examined. It was found that the counselling process was effective in reducing the costs of the work stress, sickness and 'presenteeism' in the counselling sample. However, the male and female clients responded differently. It was also seen that the counselling process was effective in producing change in work stress, particularly with respect to 'home/work interface', mental health, work and personal functioning, and in most of the coping strategies examined. The relevance of these findings is discussed in relation to implications for policy, research and practice.