The purpose of the present study is to develop a service quality scale by identifying the attributes of internal service quality delivered by small and medium manufacturing enterprises to their supplier units in order to ease their working and improve their delivery performance. 120 representatives from supplier units delivering materials and other supplies to small and medium manufacturing enterprises of North India responded to a questionnaire survey. Construct validation using exploratory factor analysis showed an interpretable latent structure consisting of four dimensions. Confirmatory factor analysis developed a valid and reliable service quality measurement scale with 16 items. It was observed that service quality of manufacturing units working towards suppliers comprises four dimensions, viz., assurance, communication, alignment and responsiveness. Snowball sampling was undertaken for this research. The scale developed in this research can be used by managers of small and medium manufacturing units in identification of opportunities for assuring service excellence to their suppliers to facilitate their working and improve performance, thereby mutually benefitting both partners as well as the whole supply chain. This research provides a framework to researchers to build more service quality scales in similar situations so that more concrete generalizations can be made.