This study has shown that microorganisms associated with caries (mutans streptococci, lactobacilli) and marginal periodontitis (Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans) in pure culture can be stored in VMGA or reduced transport fluid and be recovered sufficiently after 24 h. Sufficient recovery after 24 h of mail transport was also obtained in 37 saliva samples obtained from adults and 80 subgingival samples from a group of patients before and 3, 6 and 15 months after periodontal treatment. The samples transported in VMGA III showed in comparison to the samples transported in reduced transport fluid a higher recovery rate as well as a higher percentage of the total viable count for investigated anaerobic species. This was explained by the different composition of the two media and also by the gel consistency of VMGA III, which maintains a low redox-potential even during transport after transferring a sample into the medium. In a few samples aerobic bacteria increased in both media.