Abstract Aims Population-wide impacts of new guidelines in the primary prevention of atherosclerotic cardiovascular disease (ASCVD) should be explored in independent cohorts. Assess and compare the lipid-lowering therapy eligibility and predictive classification performance of 2016 and 2021 European Society of Cardiology (ESC), 2019 American Heart Association/American College of Cardiology (AHA/ACC), and 2022 US Preventive Services Task Force (USPSTF) guidelines. Methods and results Participants from the CoLaus|PsyCoLaus study, without ASCVD and not taking lipid-lowering therapy at baseline. Derivation of 10-year risk for ASCVD using Systematic COronary Risk Evaluation (SCORE1), SCORE2 [including SCORE2-Older Persons (SCORE2-OP)], and pooled cohort equation. Computation of the number of people eligible for lipid-lowering therapy based on each guideline and assessment of discrimination and calibration metrics of the risk models using first incident ASCVD as an outcome. Among 4,092 individuals, 158 (3.9%) experienced an incident ASCVD during a median follow-up of 9 years (interquartile range, 1.1). Lipid-lowering therapy was recommended or considered in 40.2% (95% confidence interval, 38.2–42.2), 26.4% (24.6–28.2), 28.6% (26.7–30.5), and 22.6% (20.9–24.4) of women and in 62.1% (59.8–64.3), 58.7% (56.4–61.0), 52.6% (50.3–54.9), and 48.4% (46.1–50.7) of men according to the 2016 ESC, 2021 ESC, 2019 AHA/ACC, and 2022 USPSTF guidelines, respectively. 43.3 and 46.7% of women facing an incident ASCVD were not eligible for lipid-lowering therapy at baseline according to the 2021 ESC and 2022 USPSTF, compared with 21.7 and 38.3% using the 2016 ESC and 2019 AHA/ACC, respectively. Conclusion Both the 2022 USPSTF and 2021 ESC guidelines particularly reduced lipid-lowering therapy eligibility in women. Nearly half of women who faced an incident ASCVD were not eligible for lipid-lowering therapy.