After completing his education, Hikmet Çetin joined the State Planning Organization (Turkish: Devlet Planlama Teşkilatı, DPT).

After returning home, he completed his military service in 1970 and worked as the head of Economics Planning Department at the DPT until 1977.

Hikmet Çetin stepped into politics in the 1977 general elections as deputy of Istanbul from the Republican People's Party (CHP).

Following the 1980 military coup that banned the existing political parties, Hikmet Çetin became an advisor in planning to the Government of Yemen.

In 1995, the two left wing parties, SHP and CHP decided to merge, and their general assemblies agreed on the leadership of Hikmet Çetin.

[5] Since 2013, Çetin has been a Member of the Global Leadership Foundation, chaired by FW de Klerk, an organisation that works to support democratic leadership, prevent and resolve conflict through mediation and promote good governance in the form of democratic institutions, open markets, human rights and the rule of law.