[1] After being educated at Nalanda College, Colombo Amarasinghe entered University of Ceylon and graduated with an Economics Degree with Honours.
Later on obtained MSc in Economics from McMaster University in Canada.
[2] After graduation Amerasinghe joined Central Bank of Sri Lanka as an economist.
During his tenure, he had serverved as senior economist of economic research, director data processing superintendent of public debt, controller of exchange and an executive director.
P. Amarasinghe has also served as chairman of the Institute of Bankers and the Credit Information Bureau of Sri Lanka.