Haematological and biochemical features of sixteen cases of post-parturient haemoglobinuria (PPH) from 15 farms in the Waikato and Bay of Plenty regions are described. Characteristically there was a marked regenerative anaemia as well as spherocytosis and haemoglobinaemia. Heinzbody formation occurred in 1–50% of erythrocytes depending on the case. Nine of 11 cases examined had subnormal serum inorganic phosphorus concentrations.