This article reports the results of an anonymous survey of researchers at a government research institution concerning their perceptions about ethical problems with journal peer review. Incompetent review was the most common ethical problem reported by the respondents, with 61.8% (SE = 3.3%) claiming to have experienced this at some point during peer review. Bias (50.5%, SE = 3.4%) was the next most common problem. About 22.7% (SE = 2.8%) of respondents said that a reviewer had required them to include unnecessary references to his/her publication(s), 17.7% (SE = 2.6%) said that comments from reviewers had included personal attacks, and 9.6% (SE = 2.0%) stated that reviewers had delayed publication to publish a paper on the same topic. Two of the most serious violations of peer review ethics, breach of confidentiality (6.8%, SE = 1.7%) and using ideas, data, or methods without permission (5%, SE = 1.5%) were perceived less often than the other problems. We recommend that other investigators follow up on our exploratory research with additional studies on the ethics of peer review.