The scientific publishing enterprise relies strongly on the ethics of the scientific community. The editors and reviewers of scholarly journals try to do their best to identify areas of concern when reviewing a paper for publication, but they, as much as anyone, are not immune to bias. With the tremendous pressure on researchers to publish and the huge competition to have papers accepted by high-impact journals, scientific fraud is on the rise. Fabricating results in medical research is particularly dangerous, as it could affect the well-being of many people. Although there is no system of control that can completely eliminate fraud, everything possible should be done to prevent it, because the intentional misconduct of a single author can seriously damage the reputation of a department, an institution, and a publication. This chapter discusses unethical behavior and what scientific journals are doing to detect it prior to publication.