This study investigates the service quality in the maintenance of mechanical and engineering services. The determinants of service quality are identified and their means of evaluation are examined. A method of assessment is devised based on the SERVQUAL approach, and its use is then illustrated using a small empirical survey of clients and service providers and the 'Gap' model used to quantify the relationships between customer satisfaction, expected service, perceived service and service quality gap.Client Service Provider Service Quality Expectation Perception Satisfaction,