Up to now, clear recommendations for diagnostic measures regarding mastitis control in dairy farms do not exist. The expenditure for diagnose establishment depends on the basic conditions of the given dairy farm and its goals regarding udder health. Detecting udder infections of single animals which bear risks for the entire herd needs an extensive diagnostic effort. With environmental- related microorganisms, the knowledge of their distribution within a herd is often sufficient for the choice of preventive and therapeutic measures. In cases where costs of therapy must be diminished actively, an increase of diagnostic costs is necessary to avoid undesired false developments - e. g. the quick spreading of cow-related microorganisms. The present paper discusses different possibilities of mastitis diagnostic approaches to facilitate decisionmaking processes within veterinary consultation of dairy farms.