Microbiological flora of 9 mm deep pathological pocket was studied. Samples were taken every two weeks during 3 months' time and examined using media and techniques for culturing of anaerobic bacteria. Curves, illustrating counts of anaerobic bacteria from the dark-field microscope, slide and viable counts, were similar in shape and stayed almost parallel to one another in diagram. Sample 4 was the largest out of 6 samples taken, when bacterial population was compared. Gram positive cocci were found in 3 samples, Gram positive rods in 5 samples and Gram negative cocci in 1 sample out of 6 samples; Gram negative rods in all of the samples. Gram negative motile and non-motile anaerobic rods and facultative Gram negative rods were present in 5 samples. Total viable count of bacterial population in the pocket examined changed in time, proportions of identified bacteria and related to them bacterial species changed periodically in time.