The 62-year-old Oqilov has been prime minister since late 1999.
Rakhmonov, who won a third, seven-year term on November 6, decreed on November 30 that the number of cabinet ministries and government agencies be reduced by one-third.
He also ordered the creation of a few new administrations, including an Agency for the Fight Against Corruption and Economic Crimes, which will be placed under his direct supervision.
Many ministers have retained jobs in the new administration, including Defense Minister Sherali Khayrulloev, who has served in the post since 1995.
Among the new faces is Tajikistan's envoy to the United States, Khamrakhon Zaripov, who was appointed foreign minister.
A woman, Rano Abdurakhmanova, has been appointed health minister.
(Avesta, Khovar, Tribun)