This paper aims to examine the impact of service quality and corporate social responsibility (CSR) on brand authenticity and determine the moderating effects of CSR on the relationship between service quality and brand authenticity. Survey data was collected from 472 customers of Karachi, Pakistan’s four major medical diagnostic laboratories, through the convenience sampling technique. The quantitative method was used. To collect information from respondents, a self-administered questionnaire is used. We utilized the partial least squares structural equation modeling (PLS-SEM) technique to analyze data. The results show that CSR, service quality, and brand authenticity are related in medical diagnostic and research laboratories. Research findings indicate that service quality and CSR directly and positively impact brand authenticity. In addition, CSR moderates the effect between service quality and brand authenticity. Managers can see corporate social responsibility as an intangible value that goes along with high-quality services and makes medical diagnostic and research laboratory services more authentic.