Survival of cows from four breed crosses (Hereford, BrahmanxHereford, FriesianxHereford and SimmentalxHereford) was evaluated for cows run from weaning under three different pasture systems (High, Medium and Low nutritive value). A lenient culling policy was used during the experiment, and more stringent policies based on reproductive failures were retrospectively applied to the data. Productive lifetime was modelled after a Weibull and a Cox model, and predictions from these models were compared with Kaplan-Meier estimates of survival. In terms of significance of fixed effects the two models gave similar results, but the Weibull model had a tendency to over-estimate survival, particularly at older ages. Under all culling policies the BrahmanxHereford cows had markedly (P<0.001 to P<0.0001) better survival than the other genotypes, which were similar to each other. This superior survival was attributed to a lower frequency of deaths and involuntary culls for Brahman cross cows compared to the other genotypes. Analysis of reasons for disposal also showed that BrahmanxHerefords had significantly fewer cows exiting the herd without returning any salvage value (i.e. cows dying or being culled for eye cancer) than the other genotypes. Differences in cow survival between pasture systems were small when a lenient culling policy was used. However, stringent culling on reproductive performance produced a large pasture system effect, with cow survival on the low pasture considerably lower (P<0.0001) than that on medium and high pastures. The interaction between genotype and pasture system on cow survival was not significant.