The role of agriculture sector in Sri Lanka in the process of structural transformation was examined based on the Myint Hypothesis, which suggests that as a country undergoes the structural transformation there are four different roles to be played by its food and agriculture sector, including: (1) food security - associated with annual per capita production of food; (2) labour mobility - releasing of agricultural labour force to other sectors (manufacturing and services); (3) capital formation - through domestic savings from agriculture, and (4) agriculture trade - earning of foreign exchange by exporting agriculture products. The outcome based on multivariate data analysis, which employed the principles of distributed lag models in various functional forms to the data covering the period of 1970 - 2010, shows that the performance of the agriculture sector was fairly satisfactory. The study, as a whole, highlights the importance of safeguarding this particular sector, because it acts as the mainstay of livelihood for vast majority of people and since it has the potential to stand right with an appropriate agricultural policy and institutional framework.