AIM: Description of factors relating to an outbreak of post-parturient haemoglobinuria in a dairy herd in New Zealand. HISTORY: Fifty cows out of 300 newly autumn calved cows, at about 3 weeks post partum, developed signs of anorexia, jaundice, anaemia, red urine, and 14 died. Many cows were severely inappetant. Others were subclinically affected, as indicated by partial inappetance. Routine haematological examinations carried out at this time revealed a profound regenerative anaemia, and serum phosphorus concentrations were markedly decreased, giving a diagnosis of postparturient haemoglobinuria. The cows had been through a severe drought, but were in good condition. They were being fed a combination of grass, barley and a mix of fruit, vegetable cannery waste and silage. Analysis of the grass, milker mix and silage, which formed a component of the milker mix, revealed a marginally low phosphorus concentration in the silage. TREATMENT: The cows were treated by phosphorus supplementation and supportive treatment, and most eventually recovered. KEY WORDS: Post-parturient haemoglobinuria, hypophosphataemia, anaemia, hepatic disease, phosphorus supplementation, inappetance.