Objective: To compare the effects of setting the partogram action line at 2 hours from the alert line instead of 4 hours on the outcome of labour. Methods: A prospective randomized study of 300 primigravid women with uncomplicated pregnancies, in spontaneous labour at term, was carried out at Obafemi Awolowo University Teaching Hospitals Complex, Ile Ife. Women were assigned to have their labour recorded on a partogram with action line at 2 or 4 hours to the right of alert line. The primary outcome measure was the caesarean section rate in both groups. The duration of labour, augmentation rate and the neonatal outcome as measured by Apgar scores were also compared.