The purpose of this study was to evaluate the effect of implementing the HACCP system on foodservice establishments. At first, the hygienic conditions were measured by microbiological hazard analyses of the cooking utensils and working areas. In order to solve the detected problems, the HACCP system was implemented, after what was considered a sufficient settlement period following the initial assessment, then microbiological verification was Performed again. In relation to the cooking utensils and equipment(kitchen knives. cutting boards, knives for shredding vegetables, refrigerators, baskets, barts, working tables, preparation tables, tungs, dish-clothes and drains) the microbiological inspection on the Total Plate Count, Coliforms, Staphylocaccus aureus and, Listeria monocytogenes, were conducted with regard to the working areas(working tables, preparation tables, seasoning`s shelves, serving tables, drinking water tables. refrigerators, storage rooms and dining tables), the Total Plate Count and Fungi were also examined. According to the microbiological hazard analyses there were many problems. especially with cutting boards, baskets, barts, dish-clothes and sinkballs. However. by introducing the HACCP system, the microbiological hazard levels were able to be controlled and lowered, and the total aerial bacteria in the working areas of the foodservice establishments were detected at levels below 6 CFU/plate.