AbstractBackground and aimsOptimising smoking cessation (SC) referral strategies within lung cancer screening (LCS) could significantly reduce lung cancer mortality. This study aimed to measure acceptance of referral to SC support by either practitioner‐referral or self‐referral among participants attending a hospital‐based lung health check appointment for LCS as part of the Lung Screen Uptake Trial.DesignSingle‐blinded two‐arm randomised controlled trial.SettingEngland.ParticipantsSix hundred forty‐two individuals ages 60 to 75 years, who self‐reported currently smoking or had a carbon monoxide reading over 10 ppm during the lung health check appointment.Intervention and comparatorParticipants were randomised (1:1) to receive either a contact information card for self‐referral to a local stop smoking service (SSS) (self‐referral, n = 360) or a SSS referral made on their behalf by the nurse or trial practitioner (practitioner‐referral, n = 329).MeasurementsThe primary outcome was acceptance of the practitioner‐referral (defined as participants giving permission for their details to be shared with the local SSS) compared with acceptance of the self‐referral (defined as participants taking the physical SSS contact information card to refer themselves to the local SSS).FindingsHalf (49.8%) accepted the practitioner‐made referral to a local SSS, whereas most (88.5%) accepted the self‐referral. The odds of accepting the practitioner‐referral were statistically significantly lower (adjusted odds ratio = 0.10; 95% confidence interval = 0.06–0.17) than the self‐ referral. In analyses stratified by group, greater quit confidence, quit attempts and Black ethnicity were associated with increased acceptance within the practitioner‐referral group. There were no statistically significant interactions between acceptance by referral group and any of the participants’ demographic or smoking characteristics.ConclusionsAmong participants in hospital‐based lung cancer screening in England who self‐reported smoking or met a carbon monoxide cut‐off, both practitioner‐referral and self‐referral smoking cessation strategies were highly accepted. Although self‐referral was more frequently accepted, prior evidence suggests practitioner‐referrals increase quit attempts, suggesting practitioner‐referrals should be the first‐line strategy within lung cancer screening, with self‐referral offered as an alternative.