BackgroundDepression, generalized and cardiac anxiety, and posttraumatic stress disorder negatively affect disease severity, participation, and mortality in patients with cardiovascular disease. Psychological treatments within cardiac rehabilitation may improve the outcomes of these patients. We therefore developed a cognitive-behavioral rehabilitation program for patients with cardiovascular disease and mild or moderate mental illness or stress or exhaustion. In Germany, similar programs are well established in musculoskeletal rehabilitation and cancer rehabilitation. However, no randomized controlled trials have evaluated if such programs achieve better outcomes in patients with cardiovascular disease compared with standard cardiac rehabilitation.MethodsOur randomized controlled trial compares cognitive-behavioral cardiac rehabilitation with standard cardiac rehabilitation. The cognitive-behavioral program complements standard cardiac rehabilitation with additional psychological and exercise interventions. Both rehabilitation programs last for four weeks. We enroll 410 patients with cardiovascular disease and mild or moderate mental illness or stress or exhaustion aged 18 to 65 years. Half of the individuals are randomly assigned to cognitive-behavioral rehabilitation and the other half to standard cardiac rehabilitation. Our primary outcome is cardiac anxiety 12 months after the end of rehabilitation. Cardiac anxiety is assessed with the German 17-item version of the Cardiac Anxiety Questionnaire. Secondary outcomes cover outcomes assessed by clinical examinations and medical assessments and a range of patient-reported outcome measures.DiscussionThis randomized controlled trial is designed to determine the effectiveness of cognitive-behavioral rehabilitation at decreasing cardiac anxiety in patients with cardiovascular disease and mild or moderate mental illness or stress or exhaustion.Trial registrationGerman Clinical Trials Register (DRKS00029295, June 21, 2022).Supplementary InformationThe online version contains supplementary material available at 10.1186/s12872-023-03272-1.