Background Although ICDs are appreciated by the great majority of patients a number of surveys have shown raised levels of Anxiety and Depression and reduced Health Related Quality of Life in a substantial minority of patients. We developed and evaluated a cognitive-behavioural programme, based around a printed and audio-taped self-help manual, to psychologically prepare patients for implantation and for their rehabilitation after discharge. We evaluated its effectiveness in a multicentred, intention-to-treat trial with cluster randomisation of 8 large ICD implantation centres in the UK. Patients A series of adult patients undergoing implantation with an ICD. Interventions The control group received usual care. The experimental group usual care plus the cognitive-behavioural programme delivered by an arrhythmia nurse, prior to and immediately after implantation and continuing after discharge through 4 phone contacts over 12 weeks. Main outcome measures Quality of Life (SF12), % of patients borderline' or case' for Anxiety or Depression (Hospital Anxiety & Depression Scale), Activity Limitations (Seattle Angina Questionnaire, SAQ), planned and unplanned admissions to hospital. Results 192 patients were consented. Multi-level modelling (to take into account the clustered nature of participants within centres) showed differences favouring the self-help programme in the physical component of the SF-12 (mean difference 3.08; CI 1.13 to 5.04) and the physical limitations subscale of the SAQ (mean difference 2.22; CI 0.11 to 7.22) at the 0.05 level in favour of the intervention group. Similarly, there was a greater reduction in the proportion of case of depression and anxiety between implantation and 6 months in the intervention group vs control group, 13.2% vs. 2.1% and 20.8% vs. 12.7% respectively. Significant differences were also observed in planned ECG's (88.9% vs 66.3%) and unplanned emergency admissions (11.1% vs 24.5%). Economic analysis showed the self-help manual to be highly cost effective. Conclusions: The ICD Plan a cognitive-behavioural self-management programme provides clinically worthwhile benefits to ICD patients, significantly reducing cases of anxiety and depression improving HRQOL and reducing emergency readmissions by 50%. It is simple to institute, requires very little resource and can easily be added to the existing routines.