The mating ability of 541 Merino rams from 19 different producers in the area surrounding Bloemfontein was investigated. About 23 % of the rams were not able to mate successfully with a ewe in oestrus. This figure is a combination of 7,3% rams showing no heterosexual sex interest and 15,8 % that were unable to mate successfully with an oestrous ewe within ten minutes. Age, season and frontal skinfold development did not significantly effect (P ≥0,05) the mating ability of the rams.