It is the first newly elected government since the military ousted Thaksin in 2006. There are five other parties in the coalition.
The new Cabinet's pro-Thaksin members will ensure there is no new military intervention as Prime Minister Samak Sundaravej also has assumed the post of defense minister, the Voice of America reported.
Other key Cabinet posts also are held by Thaksin allies, including Foreign Minister Nopidon Pattama, a Thaksin lawyer, the report said.
Thaksin has lived in Hong Kong in exile since his ouster.
The VOA report said Samak had openly pledged his loyalty to Thaksin but also has said he isn't the latter's puppet.
In an interview to VOA, Samak said Thaksin has no role in his government as he has been barred from entering Thai politics for five years.
The report quoted some political analysts as saying it won't be long before Thaksin is allowed to return to Thailand where he will be cleared of a pending fraud charge.