OBJECTIVE To determine the prevalence of failure of transfer of passive immunity (FTPI) and agammaglobulinaemia in calves in south-west Victorian dairy herds and identify associated risk factors for both outcomes. METHODS Cross-sectional study. METHODS Serum total protein was measured in 1018 calves from 100 south-west Victorian dairy herds. The proportions of calves with FTPI and agammaglobulinaemia were determined and logistic regression with random effects used to identify calf- and herd-level variables associated with both conditions. RESULTS In total, 38% of calves had FTPI and 8% of calves had agammaglobulinaemia. Two-thirds of herds had more than 25% of calves with FTPI. Jersey and Jersey-cross calves were less likely than Holstein-Friesian calves to have FTPI (odds ratio (OR) 0.53 and 0.57, respectively). Dairy-beef crossbreed calves were more likely to have agammaglobulinaemia than Holstein-Friesian calves (OR 3.52) and bull calves were more likely to have agammaglobulinaemia than heifer calves (OR 2.22). Removal of calves from the calving area less than twice a day was associated with increased odds of FTPI (OR 1.61) and agammaglobulinaemia (OR 1.97) relative to more frequent removal. CONCLUSIONS There is considerable potential to improve the transfer of passive immunity in dairy herds in south-west Victoria. The prevalence of both FTPI and agammaglobulinaemia is likely to be reduced by collecting calves from the calving area twice daily and hand-feeding them extra colostrum immediately after their removal from the calving area.