Cardiac surgery patients may experience stress and anxiety, negatively impacting recovery. Pharmacological treatments are frequently used but may result in side effects. We aimed to assess the effectiveness of immersive virtual reality mindfulness and music therapy in reducing preoperative and postoperative anxiety. Between March and July 2024, 36 participants were randomised to 15 min of either virtual reality (n = 19) or music therapy (n = 17) preoperatively and on postoperative day 3. Primary endpoints were anxiety levels and salivary cortisol, assessed before and after intervention using the paired Wilcoxon test. Median age was 66 (interquartile range = 58–73); 64% were male. Both music therapy and virtual reality groups showed significant preoperative Spielberger State-Trait Anxiety Inventory score reductions after intervention: music therapy from 40 (30–48) to 23 (21–24) and virtual reality from 40 (31–54) to 23 (20–35) (both p < 0.001); there was no significant difference between groups (p = 0.7). Median virtual reality immersion and absorption scores were 90/100 (interquartile range = 80–90; 80–94). Cortisol levels did not significantly change. Postoperatively, 21 patients participated (virtual reality n = 11, music therapy n = 8), showing reduced anxiety: music therapy from 31 (26–32) to 23 (20–27), virtual reality from 33 (23–41) to 24 (22–30). Results show feasibility, tolerability, and preliminary evidence of anxiety reduction, supporting further research into music therapy and virtual reality for cardiac surgery patients. The trial was registered with the International Standard Randomised Controlled Trial Number Registry (ISRCTN51014051) (https://doi.org/10.1186/ISRCTN51014051).