Purpose – This study aims to provide an understanding of the nature of corporate social responsibility (CSR) practices in a developing country, Sri Lanka. Specifically, it explores the environmental activities and social engagements of a sample from the largest 200 companies listed on the Colombo Stock Exchange. Design/methodology/approach – Data were collected through a questionnaire survey posted to 200 listed companies. Fifty-one usable responses were received. The companies were analysed based on size, ownership and geographical scale of business. Kruskal–Wallis one-way ANOVA and Mann–Whitney U tests were used for hypotheses testing. Environmental Activity Percentage Score (EAPS) and Socially related Activity Percentage Score (SAPS) were calculated to measure the extent of companies’ CSR engagement with regard to environmental and social activities, respectively. Findings – Social issues such as unemployment and poverty, the typical issues in developing countries, often override environmental issues. This is more prominent in Sri Lankan-owned companies than those with overseas ownership. The explanation for this may involve historical, cultural and religious elements. Overall, corporate managers in Sri Lanka are concerned with social issues. Practical implications – The findings indicate that environmental practices are not widespread in the Sri Lankan corporate sector. It appears that environmental consequences are not taken into account in formulating business strategies, especially by local companies. This finding may be of interest to the corporate sector, the Sri Lankan environmental authority, non-governmental organisations, the Sri Lankan Government and academics. Originality/value – This paper offers initial insights about CSR practices in Sri Lanka, and provides empirical evidence of concerns for social issues in a developing country.