Objective: The aim of the present study was to evaluate the effect of animal health on the economical success in organic dairy farms. Material and methods: Between August 2002 and September 2003, 25 corresponding dairy farms in Lower Saxony were visited regularly and data regarding economy and animal health were gathered. Results: lhe economic benefit is closely associated with the animals' individual yields. Higher profit contributions were related to a higher percentage of cows with somatic cell count of less than 100000 cells per milliliter milk. On the other hand, a higher rate of documented clinical mastitis cases and a higher frequency of hypocalcaemic paresis cases could be detected. Basically, a relation between animal health and profit in organic dairy farms was observed. However, the present survey also showed that increased milk yields may lead not only to profit optimization but also a higher incidence of diseases. Conclusion: An excellent animal health status is not absolutely combined with high economic benefits of organic dairy farms. For the simultaneous implementation of both objectives an appreciation of animal health, independent from the individual cow milk yield, is necessary. Clinical relevance: The results show that in organic farms with a high milk yield level an increased incidence of diseases can occur.