Coastal lagoons are shallow water masses, discredited from the marines as a barrier that permits water to change through one or more inputs. These fragile ecosystems have a specific type of sediments with their own characteristics. Biogeochemical processes, mostly intervened by the benthic microbial loop, are significant for understanding the relationships among the lagoon and the contiguous coastal partition. This study was conducted in the Çakalburnu Lagoon (İzmir) area, which is located at the Bay of İzmir and the area covers 67 hectares. The aim of the present study is to constitute of determining the number of different microbial communities in the lagoon sediments. We collected from lagoon sediments samples at 7 stations and we applied a Real-time qPCR assay to determine levels of archaea (ARC), methanogenic archaea (MCRA), anaerobic methane oxidation archaea (ANME 1, ANME 2a, ANME 2c), bacteria (BAC) and sulfate-reducing bacteria (SRB2) in the study. The amount of maximum abundance of archaeal and bacterial 16S rRNA gene in sediments are 2,66x1010 gene copy numbers/g and 3,89x107 gene copy numbers/g, respectively. So, it was established that the archaeal abundance was intense in the lagoon sediments. The characterization of microbial diversity is significant for the comprehension of the biological fundamentals of the ecosystem. The data presented in our study contributes to the studies on preserving ecological and microbiological balance and determining biogeochemical cycles in sensitive ecosystems such as lagoons. The research will be conducted on studies to determine the abundance levels of seasonal and annual microbial groups in the future.