By the time medical school begins, most physicians-to-be already know a great deal about screening. We have all learned from watching television that mammograms and prostate-specific antigen tests should occur once a year beginning at a certain age. Most of us have had our cholesterol levels checked and the majority of women have had several Pap smears long before their medical careers begin. This month's issue explores some of the attitudes physicians develop regarding screening and why many of us feel obligated to perform these tests, despite a frequent lack of evidence supporting their benefits.