Presidential spokesman George Charamba said the 93-yer-old was travelling for a “scheduled medical review” and would return home next week.
“His Excellency the President left this morning for Singapore for a scheduled medical review. We expect him back in the country early next week,” Charamba told state media.
Phelekezela Mphoko will be Acting President during Mugabe’s absence.
Mugabe’s departure came days after he celebrated his 93rd birthday in Matopos where he spoke about his death saying only God knew when one dies.
As Mugabe left, nurses announced that they were joining junior doctors in a two-week strike aimed at pushing the government into paying 2016 bonuses.
Without saying much, Charamba said, “His Excellency the President left for Singapore for a scheduled medical review. We expect him back in the country early next week.”
Critics say Mugabe’s routine medical trips are enough evidence that the local health system was unreliable.
Mugabe, the world’s oldest national leader, recently spent weeks in Asia on his annual vacation, returning in late January.
However, it was never officially confirmed if he had medical treatment during the vacation.
Previously, Charamba has claimed that Mugabe suffers from an eye cataract.
According to 2011 WikiLeaks report, Mugabe was, in 2008, reported to have prostate cancer and had less than five years to live.