Synopsis The dependence of carrier lifetime on temperature has been investigated for n-type and p-type germanium. It is found that with decreasing temperature the lifetime decreases, but much faster in n-type than in p-type. The results are discussed in terms of recombination through trapping states. At sufficiently low temperatures photoconductivity and carrier injection experiments show signs of minority carrier trapping in n-type samples and occasionally in p-type samples. The phenomena observed are discussed and the properties of the trapping states are deduced. These particular trapping states are shown to be not the major cause of recombination. Doping with copper or thermally quenching n-type samples gives rise to trapping as well as enhances recombination. In comparison, thermal quenching can produce more effect on the lifetime with less effect on the sample resistivity.