-In many bird species, sexing individuals accurately is impossible if no sexual dimorphism occurs. This is often particularly true for chicks. However, genomic differences between sexes exist, and molecular techniques make it possible to determine the sex at any stage, provided that a specifically-designed protocol exists. Such a protocol for the Greater Flamingo (Phoenicopterus ruber roseus Pallas) is presented here, together with results from Greater Flamingos in the wild. Received 3 March 1999, accepted 27 March 1999.