An audacious theory proposes the existence of a novel form of life—the nanobacteria (NB)—that is quite different from the ones already known, but is capable of infecting and damaging other beings, thus qualifying them as new agents of emerging infectious diseases. The theory is no less revolutionary than the famous germ theory of disease, which was put on solid ground by the efforts of Pasteur and Koch, or the one on contagium vivum fluidum, which heralded the birth of virology. Other extraordinary findings have appeared in the recent scientific literature; some have opened new perspectives and have led to immense areas of new knowledge, while others, like cold fusion or the memory of water, have passed like meteors, and are remembered as minor happenings of little hindrance to the steady advancement of science. What about NB? Are they going to be marked as milestones, or, as we fear, are they going to linger about for decades as UFOs have? “Nanobacteria” is a neologism, introduced and patented by Dr. Olavi Kajander as the name for very small bacteria-like organisms. In 1998, a seminal paper in PNAS [1] by Kajander and Neva Ciftcioglu boldly announced the discovery of an unprecedented form of life having something in common with bacteria, but so much different from the ones already known that it deserved a new name. On account of their mineralizing properties, nanobacteria have also been called calcifying nano-particles [2]. Kajander and colleagues had worked for years on their invention, but their reports were turned down by the microbiological establishment because they went against accepted paradigms. The technical details of the methods originally used to define the key features of the purported novel organism have thus been presented orally, or published in obscure journals or proceedings, and their abstracts have often been taken uncritically at their face value. Galileo Galilei was vindicated by history, Kajander and Ciftcioglu so far only by the Web: in a Google search of July, 2003 they got 3,160 hits for “nanobacteria”; with the same keyword, we now (as of January 8, 2007) get 90,500 hits with Google, and 198,000 with Yahoo. Another obstacle to the equitable assessment of the evidence is the fact that its main contributors have—legitimately—started a diagnostics and pharmaceutical business enterprise, and their papers do not always state their business connections.