Rationale: Low uptake of low-dose computed tomography (LDCT) lung cancer screening, particularly by current smokers of a low socioeconomic position, compromises effectiveness and equity.Objectives: To compare the effect of a targeted, low-burden, and stepped invitation strategy versus control on uptake of hospital-based Lung Health Check appointments offering LDCT screening.Methods: In a two-arm, blinded, between-subjects, randomized controlled trial, 2,012 participants were selected from 16 primary care practices using these criteria: 1) aged 60 to 75 years, 2) recorded as a current smoker within the last 7 years, and 3) no prespecified exclusion criteria contraindicating LDCT screening. Both groups received a stepped sequence of preinvitation, invitation, and reminder letters from their primary care practitioner offering prescheduled appointments. The key manipulation was the accompanying leaflet. The intervention group's leaflet targeted psychological barriers and provided low-burden information, mimicking the concept of the U.K. Ministry of Transport's annual vehicle test ("M.O.T. For Your Lungs").Measurements and Main Results: Uptake was 52.6%, with no difference between intervention (52.3%) and control (52.9%) groups in unadjusted (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.82-1.16) or adjusted (OR, 0.98; 95% CI, 0.82-1.17) analyses. Current smokers were less likely to attend (adjusted OR, 0.70; 95% CI, 0.56-0.86) than former smokers. Socioeconomic deprivation was significantly associated with lower uptake for the control group only (P < 0.01).Conclusions: The intervention did not improve uptake. Regardless of trial arm, uptake was considerably higher than previous clinical and real-world studies, particularly given that the samples were predominantly lower socioeconomic position smokers. Strategies common to both groups, including a Lung Health Check approach, could represent a minimum standard.Clinical trial registered with www.clinicaltrials.gov (NCT02558101) and registered prospectively with the International Standard Registered Clinical/Social Study (N21774741).