In the hope of developing a relatively simple, nondestructive way of sexing adult helmeted guineafowl (Numida meleagris ), sexual differences in body mass and in the size of head adornments of adult helmeted guineafowl sampled during the winter months in the Riemland district of the northeastern Free State, South Africa, were investigated. Males have statistically significantly larger values for all attributes than do females. However, no single attribute, nor a combination of them, can be used to sex guineafowl unambiguously.