There is much current debate surrounding the use of non-human primates (NHPs) in medical research and drug development. This review, stimulated by calls for evidence from UK-based inquiries into NHP research, takes a critical view in order to provide some important balance against papers supporting NHP research and calling for it to be expanded. We show that there is a paucity of evidence to demonstrate the positive contribution or successful translation of NHP research to human medicine, that there is a great deal of often overlooked data showing NHP research to be irrelevant, unnecessary, even hazardous to human health and to have little or no predictive value or application to human medicine. We briefly discuss the reasons why this may be so, reflect upon the consequences for future medical progress and, on the basis of our findings, suggest a more scientifically robust and promising way forward.