In order to reassess whether applying simple microbiological methods which are in step with actual practice are able to improve the identification rates of microorganisms from clinically mastitic quarters, corresponding samples previously cultured unsuccessfully (applying the recommendations of the German Society of Veterinary Medicine [DVG]) were subjected to additional culturing methods. After repeating the routine methods in n = 261 quarter milk samples with an inoculum of 0.01 mL on esculin blood agar (then culturally-negative in n = 193 cases), samples were tested for inhibitory substances and inoculum was increased to 0.1 mL. Coliforms were detected using the rapid methods. In the next step, sample sediments and the sediment after freezing were cultured. Once the samples had been tested for endotoxins, specific culture media for mycoplasms were employed. Coagulase-negative staphylococci could be isolated from 27.5% of the remaining samples, E. coli and other coliforms in 24.4%, streptococci and enterococci in 6.7%, coryneforms in 3.6% and Staphylococcus aureus in 1.6%. In 7.3% of cases, two pathogens were detected, and 17.1% of samples yielded inhibitory substances, 3.6% lipopolysaccharides. By combining different methods for analysis and moreover by increasing the volume of the inoculum, positive results became feasible where routine methods failed to produce them.