Intestinal microflora changes in ten adult and healthy subjects after storage of specimen with different modalities, temperatures and times were evaluated quantitatively and qualitatively. Aerobic components (Enterobacteriaceae, Enterococcus, Staphylococcus and Bacillus spp.) did not show considerable variations of concentration in all maintenance conditions. Anaerobic components showed different capacity of survival for every researched genus: Clostridia and Lactobacilli, even kept frozen for one month in glycerol broth at -70 degrees C, maintained a stable viable count; Bacteroides, Fusobacteria, Veillonellae and Peptostreptococci were found stable after one week, while after one month showed a loss of concentration superior to 4 Log; Eubacteria were found remarkably reduced after seven days and completely lost after one month.