Research on captive chimpanzees incurs considerable animal welfare, ethical and financial costs. Advocates of such research claim these costs are outweighed by substantial advancements in biomedical knowledge, and that the genetic similarity of chimpanzees to humans enables the former to make critical contributions to preventing, diagnosing and combating human diseases. To assess these claims, we examined the disciplines investigated in 749 studies of captive chimpanzees published from 1995-2004 inclusive, and subjected 95 randomly selected papers to a detailed citation analysis: 49.5% (47/95) of papers had not been cited at the time of this study; 38.5% (34/95) were cited by 116 papers that did not describe well-developed methods for combating human diseases; 14.7% (14/95) of these chimpanzee studies were cited by (a total of 27) papers describing well-developed prophylactic, diagnostic or therapeutic methods for combating human diseases. Close examination of these 27 human medical papers revealed that in vitro research, human clinical and epidemiological investigations, molecular assays and methods, and genomic studies, contributed most to their development. Duplication of human outcomes, inconsistency with other human or primate data, and other causes resulted in the absence of any chimpanzee study demonstrating an essential contribution, or, in most cases, even a significant contribution of any kind, towards the development of the described human treatment.