Aims The aims of this study were to evaluate: (i) the short- and long-term effects of the internet-based cognitive behaviour (iCBT) programme on symptoms of distress and fear disorder in cardiovascular disease (CVD) patients, and (ii) the association between changes in depression and changes in symptoms of distress and fear disorder from baseline to 12-month follow-up.Methods and results Secondary analysis of data collected in a randomized controlled study evaluating the effects on depression of an iCBT programme compared to an online discussion forum (ODF) in CVD patients (n = 144). Data were collected at baseline, at post-intervention (9 weeks), and at 6- and 12-month follow-ups. The results showed that symptoms of distress disorder were statistically significantly more reduced in the iCBT group than in the ODF group. For symptoms of the fear disorder, no differences were found except for avoidance, which showed a statistically significant reduction in the iCBT group. The long-term analysis in the iCBT group showed that CAQ total score and fear decreased from baseline to 6- and 12-month follow-ups, respectively. Avoidance and attention both decreased statistically significantly from baseline to post-intervention, but not between post-intervention and 12-month follow-up.Methods and results Secondary analysis of data collected in a randomized controlled study evaluating the effects on depression of an iCBT programme compared to an online discussion forum (ODF) in CVD patients (n = 144). Data were collected at baseline, at post-intervention (9 weeks), and at 6- and 12-month follow-ups. The results showed that symptoms of distress disorder were statistically significantly more reduced in the iCBT group than in the ODF group. For symptoms of the fear disorder, no differences were found except for avoidance, which showed a statistically significant reduction in the iCBT group. The long-term analysis in the iCBT group showed that CAQ total score and fear decreased from baseline to 6- and 12-month follow-ups, respectively. Avoidance and attention both decreased statistically significantly from baseline to post-intervention, but not between post-intervention and 12-month follow-up.Conclusion The results suggest that the iCBT programme targeted depression in CVD patients successfully reduced symptoms of distress disorder and to a lesser extent symptoms of fear disorder. Change in depression was more strongly associated with a change in distress than a change in fear disorder.Registration ClinicalTrials.gov: NCT02778074 Graphical Abstract