Mr Musharraf tweeted that he has boarded his flight to Karachi from the Dubai international airport, where his supporters gathered to see him off.
In Karachi, activists of Mr Musharraf's All-Pakistan Muslim League party are planning to give him a rousing welcome.
On arrival at the Karachi airport, Mr Musharraf is expected to hold a media conference since officials have cancelled permission for his rally because of security reasons. "I will arrive in Karachi today, March 24th, at 1pm & address a public rally at the airport at 5pm in the evening," he had earlier tweeted.
Mr Musharraf faces a death threat from the Tehrik-e-Taliban Pakistan, which has vowed to send suicide bombers and snipers to kill him.
But the former military ruler has dismissed the warning. "I am going home as announced. I am not scared of anything - be it the death threat from terrorists or arrest on arrival," Mr Musharraf told supporters in Dubai yesterday.
Today, before leaving his luxury flat for the Dubai airport, he kissed his 94-year-old mother goodbye.
Mr Musharraf, who is 69, has been on self-exile for over four years. He faces several cases in Pakistan, including the assassination of former prime minister Benazir Bhutto in 2007 when he was president.
But the threat of imprisonment on arrival has receded with three Pakistani courts granting him pre-arrest bail. The former president says the cases against him are unconstitutional and he is not afraid to stand trial.
Mr Musharraf seized power in Pakistan in a coup in 1999. He stepped down as President in 2008. Threatened with impeachment, he went on self-exile in early 2009. Last year, he delayed his homecoming after being threatened with arrest.
The All-Pakistan Muslim League has been trying to mobilise support for Mr Musharraf with an advertisement campaign in the Pakistan media.