Sustainability has emerged as one of the most critical factors influencing the competitiveness of maritime shipping ports. This emergence has led to a surge in research publications on port sustainability-related topics. However, despite the increasing awareness and adoption of sustainability practices, documented literature on empirical studies with survey and interview data is very limited. Moreover, the existence of validated instruments to objectively assess sustainability through sustainability practices for shipping ports in India needs to be traced. This study contributes by validating an instrument to evaluate objectively sustainability practices in shipping ports by adopting a four-stage process, starting with item identification based on an extensive literature review, instrument evaluation by subject matter experts, assessing of the instrument with suitable content validation indices, and finally evaluating the validity and reliability of the hypothesized theoretical model. For content validation, Content Validity Index, Cohens Kappa coefficient, and Lawshe’s Content Validity Ratio were computed with the assessment by a subject matter expert panel comprising six members from the port industry as well as academicians cum researchers in the field of shipping ports. The content-validated instrument was administered to 200 samples comprising officer category port employees. The measurement model was evaluated and validated using the Confirmatory Factor Analysis to assess the extent to which the measured variables represent the theoretical construct of the study and ascertain the factor structure. The empirically validated instrument met the required guidelines of model fit, reliability, and construct validity measures and was found to be a confirmed model for measuring sustainability practices in shipping ports. Structural Equation Modeling methodology was adopted to explain the variance and the path relationship between the higher-order and lower-order constructs of sustainability. The results indicate that the economic dimensions are the major contributors to the overall sustainability of the port as they drive investments in environmental and social dimensions, leading to overall sustainable development. The study’s findings will be helpful for researchers, academicians, policymakers, and industry practitioners working towards sustainability practices that contribute to sustainable growth and development in the shipping industry.