Two studies investigated people's motivations for testing, and the influence of awareness of test inaccuracies, on their intentions to undergo cancer screening tests. Study 1 used a between-subjects design in which participants stated their intentions regarding one of several screening tests with equal accuracy but with either false negative, false positive, or unspecified errors. Study 2 used a within-subjects design in which participants indicated their intentions regarding each of those screening tests. In Study 1, intentions for testing were relatively high, affected by instrumental (illness prevention) motivations, and unaffected by type of error acknowledged. Individuals with higher emotional (reassurance seeking) motivations had lower intentions to uptake tests with false positive errors. In Study 2, intentions to uptake all tests were lower compared to Study 1, and were affected by emotional motivations. Participants preferred a test with unspecified errors over tests with specified errors, and, when forced to choose, preferred tests with false negative over false positive errors. Findings are discussed in relation to Error Management Theory and Self-Regulation Theory, emphasising the need to recognise motivations, affect, and framing as important factors in informed screening decisions.