Background Health checks are promoted to evaluate individuals’ risk of developing disease and to initiate health promotion and disease prevention interventions. The NHS Health Check is a cardiovascular risk assessment programme introduced in the UK aimed at preventing cardiovascular disease (CVD). Uptake of health checks is lower than anticipated. This study aimed to explore influences on people's decisions to take up the offer of a health check. Methods Semi‐structured interviews were conducted with people registered at four general practices in South London. The interview schedule was informed by the Theoretical Domains Framework. Data were analysed qualitatively using the Framework method using NVivo for data management. Results Twenty‐seven participants invited for a health check were included in the study. Seventeen received the health check while 10 either did not attend or failed to complete the check. Five themes emerging from the data included a lack of awareness of the health check programme, beliefs about susceptibility to CVD, beliefs about civic responsibility, issues concerning access to appointments, and beliefs about the consequences of having a check. Conclusions Health check programmes need to raise public awareness to ensure that people are informed about the objectives and nature of the programme in order to reach an informed decision about taking up the invitation. Emphasizing the benefits of prevention and early detection might encourage attendance in those who are reluctant to burden the public health‐care systems. Extending outreach initiatives and increasing ‘out of hours’ provision at local community sites could facilitate access.