[en] The Pilanesberg Complex is situated in Bophuthatswana about 50km to the north north-west of Rustenberg in the Western Transvaal. The basic geological setting of the Pilanesberg is discussed, as well as its geochemistry. Of the major rock types the co-called Ledig foyaite has the highest content of trace elements and this is followed by green foyaite. The Th/U ratio is approximately 5 for the complex as a whole. The high concentrations of uranium and thorium resulted in a pronounced radiometric anomaly over the whole complex, the details which are given in tables. The occurences of relatively high radiometric anomalies located during ground surveys are also described