Factors influencing the recalving rate of 2 165 lactating beef cows of four pure breeds (Afrikaner, Hereford, Bonsmara and Simmentaler) and three cross-bred types were investigated on the Mara Research Station between 1972 and 1982. Average recalving rate was 88.3%. The influence of year, breeding group, cow age, date of calving and body mass at four stages was investigated. Recalving rate differed significantly (P ≤ 0.05) between years varying from 76.2 to 92.5%, but significant year X breeding group (P ≤ 0.01) and breeding group X date of calving (P ≤ 0.05) interactions were also indicated. Body mass was unimportant (P > 0.05) as a predictor of recalving rate. However, cows with average body mass were more inclined to recalve than those with extreme body masses.