[2] With the formation of the Ceylon Army in October 1949, he was commissioned as a captain in the regular force in February 1950.

In January 1951, Captain Ramayanayake was one of three officers selected for training at the Royal School of Military Engineering.

Promoted to colonel, he was appointed commander, Task Force Anti Illicit Immigration in February 1969 and served till July 1970.

He was recalled to active service soon after the start of the 1971 JVP insurrection and was appointed military coordinating officer for the Galle District.

Ramanayaka Memorial Sports Ground was named after him at the regimental headquarters of the Sri Lanka Engineers.