Nowadays only a small amount of literature exists concerning phytotherapy, especially therapy of cattle, in veterinary medicine. Nevertheless farmers often apply medicinal plants to their cattle, a fact shown in a questionnaire. Looking back in history, medicinal herbs played a considerably more important part in the therapy of cattle in the past than today. In 18 selected books published between 1664 and 1899, one can find 260 plants traditionally used (LUDWIG, 1996). Those 20 medicinal plants used most frequently by farmers treating diseases of cattle are critically reviewed for their usefullness, with the background of today's valid knowledge of their effects and indications. For the lack of literature on phytotherapy in veterinary medicine it was necessary to study the corresponding literature in human medicine. Although a major part of the medicinal herbs found require more detailed clinical studies, not only on cattle but also on other animal species, valuable information for future scientific investigations could be obtained. Next tasks would concern the search for the most effective dosage of phytotherapeutics for different animal species. After solving some of these problems, phytotherapeutics could be applied more often in veterinary practice based on scientific background.