The aim of this study was to assess variations in surgical stage distribution in 2 centres within the same UK region. One centre was covered by an active screening program started in November 2018 and the other was not covered by screening. Retrospective analysis of 1895 patients undergoing lung resections (2018-2022) in 2 centres. Temporal distribution was tested using Chi-squared for trends. A lowess curve was used to plot the proportion of stage 1A patients amongst those operated over the years. The surgical populations in the 2 centres were similar. In the screening unit (SU), we observed a 18% increase in the proportion of patients with clinical stage IA in the recent phase compared to the early phase (59% vs 50%, P = 0.004), whilst this increase was not seen in the unit without screening. This difference was attributable to an increase of cT1aN0 patients in the SU (16% vs 11%, P = 0.035) which was not observed in the other unit (10% vs 8.2%, P = 0.41). In the SU, there was also a three-fold increase in the proportion of sublobar resections performed in the recent phase compared to the early one (35% vs 12%, P < 0.001). This finding was not evident in the unit without screening. Lung cancer screening is associated with a higher proportion of lung cancers being detected at an earlier stage with a consequent increased practice of sublobar resections.