This compendium is the result of the FEMS Workshop on "Rapid Diagnosis of Mycoplasmas" which I organized and which took place in Jerusalem, Israel, August 11-23, 1991. The first week's sessions were held at a resort on the outskirts of Jerusalem and consisted of lectures and discussions. This part was modelled along the lines of the Gordon Conference in the USA, i.e., in an intimate atmo- sphere in which everyone could mix and exchange ideas, and was very benefi- cial. About 100 scientists from around the world attended the first week. Dur- ing the first week, the biology, molecular biology and pathophysiology of myco- plasmas, as well as all the main diagnostic methods were covered, including both conventional and the newer technologies. The session on mycoplasmas in the human urogenital tracts was held in conjunction with the Israel Society for the Study and Prevention of Sexually Transmitted Disease. The second week was a laboratory session and was held at the Hebrew University-Hadassah Medical School campus in Ein Karem, Jerusalem. All ex- periments were conducted by eminent specialists in their field. The lab session had 36 participants from 19 countries who used the most modern techniques for the diagnosis of mycoplasmas in medicine, veterinary medicine and agri- culture. The efficacy of several commercial kits were also tested at this time. I want to again thank everyone who helped and supported this work- shop, as well as the authors of the various chapters.