The behaviour of Gd impurity in Bridgeman grown lead telluride crystals and the effect of Gd on the electrical properties and magnetic susceptibility of Gd doped crystals are studied. Gd is shown to behave like a donor impurity, although not in the usual sense of the word, and can cause PbTe crystals to become paramagnetic. Electronic conduction of Gd doped crystals is explained as resulting from a change in the relation between point defect concentration in the metal subsystem and that in the Te subsystem in favour of the latter. The Gd distribution along ingots can be accounted for only by assuming that the Gd segregation coefficient increases as the melt becomes Gd depleted.

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