A requirement of any modern pharmaceutical enterprise, which acquires even greater importance in view of the requirements of the GMP, is thorough monitoring of the quality of drugs. In order to provide conditions for adequate testing, new laboratories are created and existing ones are modified so as to provide for an increased level of analyses. In designing new and/or reconstructing old rooms for laboratories engaged in studying specific microbiological problems, it is necessary to take into account a number of special features crucial for the proper functioning of such quality monitoring departments. Below we present a project of the design, equipment, and functioning of that part of a microbiological laboratory where the tests for drug sterility are to be conducted. A Microbiological Laboratory engaged in testing drugs for injection with respect to sterility must be designed so as to meet the following requirements. (i) The laboratory must be isolated from other parts of the department. (ii) Restricted entrance of visitors (only the laboratory staff is admitted). (iii) “Clean rooms” (sterile box and lock room) must be arranged as far as possible from the laboratory entrance and not to adjoin other rooms with increased humidity and unstable atmosphere (glassware washing, media preparation, sterilization treatment) in order to reduce the risk of contamination of the “clean rooms.” (iv) “Clean rooms” (sterile box and lock room), where the sterility tests are conducted, must not have windows nor allow entrance from the common corridor. (v) The doors of “clean rooms” (sterile box and lock room) must be provided with blocking facilities, whereby the box entrance is blocked when the door to the lock room is open. (vi) The laboratory head cabinet and product stock room should be arranged as close as possible to the laboratory entrance. The dimensions of working rooms depend on the number of table and ground based instruments, the number of personnel, and the furniture employed. The rooms must be large enough to reduce the risk of cross contamination and provide for the free passage and accuracy of operation of the laboratory staff. The equipment should be positioned both near walls and at the center of working rooms. Special working tables should be placed at the sites of minimum vibration so as to avoid draughts and exposure to direct sunlight, or mounted on cantilevers fastened to the bearing wall. The inner walls must be smooth, made of noninflammable materials resistant to detergents and disinfecting agents. Possible materials are, for example, epoxy-based paints and glazed tile or special nonporous nonshining ceramics. The ceiling must be smoothly painted. The rooms must be protected against factors such as high temperature, dust, humidity, steam, noise, vibration, etc., so as to correspond to all labor safety and ecology requirements. The rooms must be well illuminated with hermetic luminaries. The temperature and humidity must be permanently controlled. In the ideal case, there must be no opening of windows in the laboratory. The air should be supplied from an air-conditioning system (15-fold recycling per hour) or via filters (5 m thick) from outside. Reliable (uninterrupted) electric power and tap water supply are necessary conditions. The laboratory furniture must be made of noninflammable materials resistant to chemical factors (plastic-coated wood). Figures 1 and 2 show an example of the microbiological laboratory design, indicating positions of the main equipment and the directions of air flows in the working rooms.