Ugandan President Yoweri Museveni has agreed to the controversial anti-homosexuality bill, despite condemnation of Western countries and human rights activists.
The bill was first passed by MPs in March but was returned to the parliament for amendment.
In the new law, the offence of homosexuality is now limited to gay sexual acts. People convicted under this clause face life imprisonment.
The legislation also prescribes death penalty for aggravated offences, in cases of sexual abuse against a minor, a disabled person or where a victim of abuse is infected with a life-long illness.
Members of the public will also be required to report to the authorities any form of homosexual abuse against children or other vulnerable people.
They said it would obstruct health education and outreach on Aids, noting that LGBTQ people were increasing fearful of their safety and security and that more people were being discouraged from seeking vital health services.
It is likely that the law will be challenged in court.
A similar one was struck down by the Ugandan constitutional court in 2014.