Her move came amid reported lobbying for cabinet seats among Pheu Thai Party factions following Mr Yongyuth's resignation last week.
Ms Yingluck yesterday said there would be no immediate cabinet reshuffle as the government wanted to speed up flood prevention measures and solve problems affecting people.
Mr Yongyuth decided to quit the cabinet after the National Anti-Corruption Commission found him guilty of malfeasance in the Alpine land case while he was a deputy permanent secretary for the Interior Ministry in 2002.
Ms Yingluck yesterday assigned Deputy Interior Minister Chuchart Hansawat to serve as acting interior minister.
Deputy Prime Minister Chalerm Yubamrung has been assigned to oversee the Interior Ministry, the Office of the Public Sector Development Commission and the Southern Border Provinces Administration Centre, which were previously under the supervision of Mr Yongyuth.
Deputy Prime Minister and Finance Minister Kittiratt Na-Ranong will supervise the Transport Ministry, while Deputy Prime Minister Yutthasak Sasiprapa will supervise the Social Development and Human Security Ministry.
Those roles were undertaken by Mr Yongyuth when he was deputy prime minister.
A source at the ruling Pheu Thai Party said that when the time comes, the cabinet reshuffle will involve at least 10 posts.
A final decision on who will be given cabinet posts will rest with members of the Shinawatra family, including ousted prime minister Thaksin, his ex-wife Khunying Potjaman na Pombejra, his younger sister Yaowapa Wongsawat and Mrs Yaowapa's husband Somchai Wongsawat, said the source.
Key members of several factions in the ruling party reportedly plan to meet Thaksin in Hong Kong this weekend to lobby for cabinet seats.
Meanwhile, Democrat Party leader Abhisit Vejjajiva said a no-confidence motion in the government is expected to be filed by the end of this month, with a debate taking place in mid-November.
Mr Abhisit believes Ms Yingluck does not want to reshuffle her cabinet for the time being after only one year in office.
If there was a shake-up, the prime minister, who has been in politics only a short period, would have to start working with a new team of ministers from square one, he said.
Those who were made ministers might not think Ms Yingluck was their boss as they were given the posts by her elder brother, he added.
Mr Abhisit said that if a cabinet reshuffle helped boost the efficiency of the government or improve the economy, everyone would support it. If the shake-up was not likely to make things better, the government should not take that course, he warned.