Born in Cape Town, Toms served two years in the South African Defence Force, conscripted after completing medical training in 1976. A committed Anglican, Toms worked as a doctor for over a decade in the Crossroads squatter camp in the Cape Flats, and became active in the End Conscription Campaign (ECC). Toms was the only doctor in the town, providing medical care for more than 60,000 people.

He was also active in the pioneering anti-apartheid Organisation of Lesbian and Gay Activist, and had met with leaders of the African National Congress in exile in Harare to discuss gay rights.

Called up for periodic service in the Defence Force in July 1987, Toms refused and was charged, tried and sentenced to 18 months gaol. Although his homosexuality was downplayed by the ECC, he was subject to a long and very public campaign of anti-gay vilification, graffiti and death threats.

The prosecution raised the issue of his homosexuality in the trial, and his lawyer, Edwin Cameron, called Anglican Bishop David Russell to testify on his behalf; he politely endorsed Toms' fight against gay oppression. Toms was released on bail after nine months in Pollsmor prison, pending an appeal, which was successful.

He has subsequently worked in progressive non-government organisation providing health anf HIV services in Cape Town. Since his appointment as director of health in 2002, Toms has helped his nation battle HIV/AIDS, tuberculosis and many other diseases. He also pioneered use of antiretrovirals. Dr. Ivan Toms died in his home of meningococcal meningitis. He was 55.