The general aim of this thesis was to describe self-reported health-related quality of life (HRQoL) in recipients with an implantable cardioverter defibrillator (ICD) due to life-threatening arrhythmias over a S-year period. The design was prospective and longitudinal. Fifty-six patients participated in Paper I, and 35 of these patients, who had survived at least five years, were included in Paper II. All patients had received their ICD as a form of secondary prevention. The Quality of Life Index-Cardiac version (QLI-C), Mishel Uncertainty in Illness Scale-Community version (MUIS-C), and multiple regression analysis were used. Higher scores indicate higher HRQoL and uncertainty. The questionnaires were completed on four occasions: before implantation, at three months and at 1 year and 5 years after implantation. ICD recipients were also asked how many shocks they had perceived. At the S-year data collection, the  average ICD recipient had lived with an ICD for 6 years and 9 months. In general, HRQoL was lower at year 1 than at baseline (p : 0.033). A decrease in the socioeconomic domain was observed at year 1 (p : 0.006) but improved again at year 5 (p : 0.027) although it remained below the baseline value, ICD recipients' satisfaction with the family domain decreased from the time of the ICD implantation (p < 0.001) and from year I (p : 0.039) to year 5 after implantation. Uncertainty related to information had  decreased at year 1 in relation to baseline (p < 0.001). A decrease in overall uncertainty was observed at year 5 in relation to year 1 (p : 0.009) as well as at year 5 in relation to baseline (p : 0.009). The longer the ICD recipient had lived with the device, the greatil the risk of receiving a shock. However, ICD recipients who  received shocks reported being less troubled by them over time. Uncertainty was identified as a predictor of low HRQoL. The recipients reported a higher level of HRQoL at year 5 than at year 1. HRQoL was reasonably good 5 years after implantation, and the ICD recipients felt more secure and perceived their ICD as a lifesaver.