Redundant publication in biomedical sciences is the presentation of the same information or data set more than once. Forms of redundant publication include “salami slicing”, in which similar text accompanies data presented in disaggregated fashion in different publications and “duplicate or multiple publication” in which identical information is presented with a virtually identical text. Estimates of prevalence of the phenomenon put it at 10 to 25% of published literature. Redundant publication can be considered unethical, or fraudulent, when the author(s) attempt (...) to conceal the existence of duplicate publication from editors and readers. Redundant publication in the area of clinical trials is potentially dangerous as it tends to overestimate the effects of interventions. The scientific community at large and governments should take urgent steps to safeguard the public from the possible effects of fraudulent multiple publications. (shrink)