Environmental technetium is an important radioelement to which consideration must be given in order to guarantee safety in nuclear waste disposal. Various analysis methods for micro and ultramicro quantities of technetium are being developed and their merits and demerits are being evaluated. The behavior of technetium in the atmosphere, sea water, soils, plants and animals, as reported by many researchers, are summarized. In particular the interaction between technetium and organic matter (such as humic acid) is noted. Finally, the geochemical migration behavior of ruthenium and technetium in the Oklo natural reactors is described as a natural analogue to radioactive waste disposal.