Before joining the SPLM in early 1990s, he held the position of Director General of the Ministry of Agriculture from 1983 - 1986, and from 1986 - 1989 he was Minister of Finance and Economic Planning in the Equatoria Regional Government based in Juba.

[1] From 1995 to 2004, Samson Kwaje was put in charge of information desk in the Sudan People's Liberation Movement/Army and became its official spokesperson.

Samson Kwaje was the head of the presidential campaign team for the SPLM Chairman and current President, Salva Kiir.

On Sunday November 15, 2009 an ambush on his vehicle outside Juba, in Central Equatoria State, resulting from a localized political issue, wounded Kwaje and killed five others.

[4] Kwaje died after three weeks in intensive care at the Aga Khan Hospital in Nairobi, Kenya, on Sunday 1 August 2010.