Chacko obtained his B. A. and L.T. (present day Bachelor of Education) degree from University of Travancore (present day University of Kerala). Later he joined the Syrian Christian Seminary School (SCS), in Thiruvalla as a teacher.
He was a member of the Indian National Congress and was a freedom fighter. In 1960, he stood representing Thiruvalla constituency for Kerala Legislative Assembly election and won. Opposing him was P. T. Punnose, a veteran Communist party leader.
P. Chacko died in 1978.