The age structure transition that has taken place in the past decades in Sri Lanka has produced a demographic dividend, covering the period from 1991 to 2017, which is conducive for an economic takeoff of the country. The dependency ratios imply that there is a likelihood that the present age structure would have a favourable impact on the economy. Around 2006, the Sri Lankan population had the best demographic environment or the ‘window of opportunity’ by recording very low rate of dependency. This is an opportunity that needs to be used before the onset of demographic turbulence, primarily resulting from population ageing. If this opportunity is missed-out, the planners will have to address the consequences of an increasing dependency burden, which would further depress the efforts for required economic development. The mere existence of a favourable demographic divided would be ineffective without a proper environment for economic acceleration. An increasing working age population seeking gainful employment, but with no proper job opportunities will be a dilemma to a country. Nevertheless, in a congenial environment of political stability and peace, adequate savings, investment potential, human capital and the knowledge economy, the optimum utilisation of the demographic bonus to gain economic acceleration would materialise. It is essential that the economic planners in the country should immediately identify the growth sectors of the economy in order to generate sufficient amount of employment for the influx of workers to the labour market during the period of the demographic dividend.