Malaysia went into mourning the death of Endon Mahmood, the popular wife of Abdullah Ahmad Badawi, from breast cancer.
Her funeral, held soon after her death on Wednesday, was nationally televised.
Parliament adjourned and local television and radio stations broadcast prayers and sombre music as a mark of respect for Endon Mahmood, who was 64.
The prime minister and his wife had been married for 40 years, and had what was seen as a model partnership.
When asked by reporters if he was coping well, Mr Abdullah smiled weakly and said: "We'll see," the Associated Press reported.
The death came in the holy month of Ramadan, during which devout Muslims believe the departed receive special blessings.
The soft-spoken Endon was diagnosed with cancer soon after her twin sister Noraini discovered she had the disease in 2002.
"I am blessed to have cancer at this time of my life because the greatest gift has been the prayers from everyone, including those from other religions," Endon said in an interview last year.
"There have been many times when people have come up to me and said that they are praying for me. I thank them all."
Officials said the public would be allowed to file past the body and pay their last respects from 11 a.m. to 4 p.m. at the prime minister's turquoise-domed residence.
Then the body will be taken to a nearby mosque for prayers before being buried in a public cemetery in Putrajaya.
Within hours of hearing the news, dozens of people stood in light rain outside the prime minister's residence. Inside, Endon's body was being washed and prepared to lie in state, wrapped in the customary white linen, officials said.
Former Prime Minister Mahathir Mohamad was among the first visitors to arrive. He went in and started reading verses from the holy Koran, officials said, reports Reuters.