Expressway construction projects are one of the crucial infrastructure projects for a country. Hence, assessment of environmental and social implications prior to initiation of the expressway construction project is vital. Thus, the research aims to analyse effect of social and environmental factors on expressway construction in Sri Lanka. Initially a comprehensive literature review was done to discuss on expressway construction in Sri Lanka and environmental and social implications of expressway construction in global context. The study followed a qualitative approach. Hence, four expert interviews were carried out to explore more on the same context limiting to Sri Lanka. Experts were selected from only on-going expressway project in Sri Lanka, central expressway project. Moreover, collected data were analysed through manual content analysis. The study findings highlighted viaduct construction, land acquisition and rock blasting as the major activities relating to environmental implications of the expressway construction projects. Thus, rational, logical, scientific, and technical selection of the routes is the most effective and efficient mean in minimizing adverse impacts. Hence planning of these activities should be done with due care by authorities only after proper feasibility studies. Further, major factors affecting social implications of the expressway construction have been identified as settlement, livelihood, public infrastructure and health and safety. Hence, resettlement action plans need to be updated to comply with the identified requirements through environmental and social factors.