Since the publication ofRadiochemistry of Germanium (NAS-NS-3043) in 1961, there have been significant developments on the subject. During the period from 1970 to 1980, the diagnostic utilization of the68Ge68Ga generator system in nuclear medicine stimulated research in the field. In addition, over the past 30 years there have been many advances in the analytical chemistry of germanium (Ge), owing to the rapid increase in application of Ge in the electronics industry and, most recently, as an important component in infrared spectrometers.This fatest review has been completely rewritten. A literature search has been completed through December of 1990. Literature for selected topics has been surveyed through September 1993. The first section contains general information about germanium and its radioisotopes, and relevant nuclear data in tabulated form. In the second section, a general review of the inorganic and analytical chemistry of Ge is presented. Following these two introductory sections, subsequent sections deal with the production and preparation of germanium radioisotopes, separation and determination of Ge, of particular interest to the radiochemist, and selected procedures for its determination in or separation from various media. The section on separation chemistry has been greatly expanded.The review includes sections on hot-atom chemistry and the chemical behavior of carrier-free68Ge. A section entitled Applied Radiochemistry of Germanium deals specifically with68Ge68Ga generator systems, the role of71Ge in the detection of solar netrinos, and the preparation of68Ge positron sources for studying dislocations in metallic lattices and calibration of Positron Emission Tomography (PET) cameras.Two other noteworthy points follow. Throughout the text, the oxidation state of a metal ion having only one stable state, such as germanium, is not explicitly indicated. Therefore, Ge typically represents Ge4+. Other ions such as arsenic and tin, however, are indicated with their appropriate oxidation states. The term carrier-free applies to radioactive preparations to which no isotopic carrier (stable isotopes) is intentionally added.