Cost-effectiveness analysis (CEA) presenting a cost/QALY ratio is considered the gold standard for economic evaluations in healthcare. Despite the proliferation of CEA research, there has been no detailed study focusing on the bibliometric properties of this literature. To describe and analyze trends in publications and co-authorship in the CEA literature from 1976-2005. We used the Tufts-New England Medical Center registry of original CEAs published through 2005 (http://www.tufts-nemc.org/cearegistry/). For each article we recorded the year of publication, journal's name, the number of contributing authors and their names. Authors were assigned a credit based on their perceived contribution to the study (1 credit point for the first and last authors, ½ point for the second author, and 1/n credit points for all other authors). We calculated the Author's Contribution Index (ACI), by dividing the total credit points by the number of studies published by the same author. Approximately 1150 studies have been published in 360 journals over the past 30 years, with an increase in the number published annually from 18(±26) in 1976-2000 to 138(±46) in 2001-2005, p<0.0001. The mean number of contributing authors was 4.6(±2.4) and increased from 4.3(±2.3) to 4.8(±2.5), p<0.0001 over that same time interval. Medical journals were characterized by a higher number of co-authors, as compared with the economic and health policy literature: 4.7(±2.4) vs. 4.2(±2.1), p=0.004. The lowest number of co-authors (3.6) was in Value in Health and Medical Decision Making, and the highest in Circulation (7.7). The most prolific authors were affiliated with Harvard and Tufts Universities. Conclusions: The CEA literature continues to proliferate. Co-authorship trends seem to follow the rapid increase in the mean number of authors found in the health economics and medical literature. Further research is needed to examine journals' and authors' concentration trends, and dissemination of CEA results.