Aims A paucity of studies in implantable cardioverter-defibrillator (ICD) patients has examined gender disparities in patient-reported outcomes, such as anxiety and quality of life (QoL). We investigated (i) gender disparities in anxiety and QoL and (ii) the magnitude of the effect of gender vs. New York Heart Association (NYHA) functional class (III/IV), ICD shock, and Type D personality on these outcomes. Methods and results Implantable cardioverter-defibrillator patients (n = 718; 81% men) completed the State-Trait Anxiety Inventory (STAI) and the Short-Form Health Survey 36 (SF-36) at baseline and 12 months post-implantation. The magnitude of the effect was indicated using Cohen's effect size index. Multivariate analysis of covariance for repeated measures showed no differences between men and women on mean scores of anxiety (F((1,696)) = 2.67, P = 0.10). Differences in QoL were observed for only two of the eight subscales of the SF-36, with women reporting poorer physical functioning (F((1,696)) = 7.14, P = 0.008) and vitality (F((1,696)) = 4.88, P = 0.028) than men. With respect to anxiety, effect sizes at baseline and 12 months for gender, NYHA class, and ICD shocks were small. A large effect size for Type D personality was found at both time points. For QoL, at baseline and 12 months, the effect sizes for gender were small, while the influence of NYHA class and Type D personality was moderate to large. Conclusions Men and women did not differ on mean anxiety or QoL scores, except for women reporting poorer QoL on two domains. The relative influence of gender on anxiety and QoL was less than that of NYHA functional class and Type D personality.