In order to expand upon the limited literature estimating the quantity and quality of worldwide research production in the field of microbiology, a bibliometric analysis was conducted for the period 1995-2003 using the PubMed and Journal Citation Reports databases. By searching the "microbiology" category of the Journal Citation Reports database, a total of 74 journals were identified that were also included in PubMed. From these journals, a total of 89,527 articles were identified for analysis, and data on the country in which the research originated was available for 88,456 (98.8%) of them. The individual countries were separated into nine world regions. In terms of research production for the period studied, Western Europe exceeded all other world regions, with the USA ranking second. The mean impact factor was highest for the USA at 3.4, while it was 2.8 for Western Europe and 2.4 for the rest of the world combined. The research productivity per unit of expenditure for research and development was higher for Canada and Western Europe than for the USA. The three regions in which research productivity increased the most were Asia, Latin America, and Eastern Europe.