The study investigates and interprets the factors that contributed to the recent decline in fertility in Sri Lanka, despite its low economic standing. It seeks to elucidate the social transformation that has taken place and looks at the socio-cultural determinants that have brought about the process of fertility transition. In this regard, the significant effects of the welfare measures in force in the country in respect of health, education, nutrition and housing have been brought to light. Hence the study tends to fall outside the scope of the conventional wisdom laid down in the demographic transition theory outlined by Notestein, which emphasised the contribution that economic development plays in lowering fertility. The approach to the study hinges on selected variables like education, age at marriage, gender roles per se and female employment. The cardinal role played by free education in contributing to the transition is given particular coverage. Education is treated more as a cultural asset which determines and shapes values, preferences and aspirations in respect of marriage, fertility, family formation and other aspects such as career development which enables women to play roles away from home. Unfortunately, inferences about women's position do not always gain statistical support, as they are intricately woven into the fabric of societal gender settings and traditions. In respect of age at marriage, the socio-cultural factors of society like the caste system, a dowry and horoscope matching with details of Karmic determinants have been examined in some detail. The study also uncovers the social deprivation aspects which for long led women in the plantation sector to experience fertility performance lower than the national level. Going by normal demographic rationale, their high degree of labour force participation should account for it. But it was social deprivation and the resultant low nutritional levels that reduced their reproductive ability to low levels. With a better life ushered in by a programme of social uplift during the early 'eighties, this ethnic group showed signs of first a rise in fertility, and on having reached the threshold it has now begun showing signs of a decline attributable to healthier lives. Similarly, a relatively invisible agent, the prevalent “urban outlook," is shown to contribute to the transition process, and has recently become even more significant due to the intensive rural amelioration efforts of the government. This outlook is all pervasive and permeates the society in general in effecting the transition under review