GMP problems associated with microbiological environmental monitoring are among those most commonly cited as objectionable during FDA inspections of parenteral drug manufacturing facilities. This presentation describes FDA inspection approaches and techniques and audit applications used in evaluating the effectiveness of firms environmental monitoring programs. Environmental monitoring programs involve considerable data, and many variables are interrelated to make difficult detection of patterns and trends during FDA audits. Consequently, systematic computer-aided audit techniques have been developed by the author to permit detection of patterns, trends and GMP documentation problems by the FDA. The strategies and techniques described in this paper may provide management with ideas about ways to review and audit their own environmental data. Presented are some practical details about the use of a portable computer to systematically assess trends and patterns. Several program applications (algorithms) were developed to determine if cleanroom environmental data are under a state of control.