Three separate 48 h observations were made of the suckling behaviour of 1. (1) Hereford × Friesian cows under grazing conditions, 2. (2) Blue Grey cows under grazing conditions, and 3. (3) Blue Grey cows housed. All the cows suckled Charolais cross calves. The mean suckling frequencies recorded were 5.5, 5.5 and 9.1 times per 24 h in the first, second and third study, respectively. A trend for older calves to be suckled less frequently was observed in all three studies, although this was not significant. Milk yield of the cow was considered a possible factor involved in determining suckling frequency. A relatively uniform distribution of suckling throughout the "day" was recorded in the second and third study, with three peaks of suckling activity apparent in the first study. The mean duration of suckling was 6.9, 10.7 and 10.6 min in the first, second and third study, respectively.