Aims <p>Cognitive decline is common after cardiac surgery and is associated with poor postoperative outcomes. The aim of this study was to evaluate the feasibility and acceptability of a home-based computerised cognitive training programme to improve POCD following cardiac surgery; this study was not designed to assess the efficacy of the intervention.</p> Methods <p>This single-arm, non-blinded, feasibility and acceptability study included patients ≥ 18&#xa0;years undergoing first-time elective cardiac surgery using standard extracorporeal circulation. Participants were required to complete an 8-week computerised cognitive training (CCT) programme (20&#xa0;min/day; 5&#xa0;days/week), commencing 1&#xa0;week after surgery. The Montreal Cognitive Assessment (MoCA) was administered preoperatively and after programme completion. Feasibility outcomes included recruitment and retention rates and programme adherence. Acceptability was assessed by the Theoretical Framework of Acceptability Questionnaire (TFA-Q).</p> Results <p>Twenty-nine participants were recruited: 7 (24%) were female and 20 (69%) were White British. Study recruitment was deemed to be feasible (61% of eligible patients) and the CCT was acceptable to 94% of participants who completed the TFA-Q (<i>n</i> = 16), noting that this does not reflect the full recruited cohort. Intervention adherence (<i>n</i> = 9, 31%) and study retention (<i>n</i> = 17, 59%) were limited.</p> Conclusions <p>The findings of this feasibility study suggest that home-based CCT is deliverable and acceptable to patients following cardiac surgery, though strategies to improve retention and adherence will need to be strengthened before progression to an efficacy study.</p> Trial registration <p>NCT05298540.</p>