Abstract: Background: Patient preferences derived from an assessment of values can help inform the design of screening programs, but how best to do so, and whether such preferences differ cross-nationally, has not been well-examined. The objective of this study was to compare the values and preferences of Australian and US men for PSA (prostate specific antigen) screening. Methods: We used an internet based survey of men aged 50-75 with no personal or family history of prostate cancer recruited from on-line panels of a survey research organization in the US and Australia. Participants viewed information on prostate cancer and prostate cancer screening with PSA testing then completed a values clarification task that included information on 4 key attributes: chance of 1) being diagnosed with prostate cancer, 2) dying from prostate cancer, 3) requiring a biopsy as a result of screening, and 4) developing impotence or incontinence as a result of screening. The outcome measures were self reported most important attribute, unlabelled screening test choice, and labelled screening intent, assessed on post-task questionnaires. Results: We enrolled 911 participants (US:456; AU:455), mean age was 59.7; 88.0% were white; 36.4% had completed at least a Bachelors' degree; 42.0% reported a PSA test in the past 12 months. Australian men were more likely to be white and to have had recent screening. For both US and Australian men, the most important attribute was the chance of dying from prostate cancer. Unlabelled post-task preference for the PSA screening-like option was greater for Australian (39.1%) compared to US (26.3%) participants (adjusted OR 1.68 (1.28-2.22)). Labelled intent for screening was high for both countries: US:73.7%, AUS:78.0% (p=0.308). Conclusions: There was high intent for PSA screening in both US and Australian men; fewer men in each country chose the PSA-like option on the unlabelled question. Australian men were somewhat more likely to prefer PSA screening. Men in both countries did not view the increased risk of diagnosis as a negative aspect, suggesting more work needs to be done on communicating the concept of overdiagnosis to men facing a PSA screening decision. Trial registration: This trial was registered at ClinicalTrials.gov (NCT01558583).