Two of them have alleged sexual assault and a third says he exposed himself to her when she was 16.
Last month 80-year-old Hoffman, who has also been nominated for five Oscars, was accused by three other women of unwanted sexual advances for which he apologised “if he had done anything wrong”.
In fresh allegations reported in Variety, playwright Cori Thomas said Hoffman exposed himself in 1980 after an outing with him and his daughter Karina, who was a schoolfriend.
She said he walked out of a hotel bathroom wearing only a towel which he dropped while they were alone as she waited for her parents.
Ms Thomas added: “It was the first time I had ever seen a naked man. I was mortified. I didn’t know what to do. And he milked it.”
A second woman, Melissa Kester, said she “felt like she’d been raped” after Hoffman allegedly assaulted her while they were in a booth recording songs for the 1987 film Ishtar.
“There was no warning. I didn’t know he would do that,” she said.
And another unnamed woman claimed Hoffman assaulted her on the back seat of a car after the wrap party for Ishtar, and they later had consensual sex.
Hoffman has not personally responded to the latest allegations but his legal representatives described the claims as “defamatory falsehoods”.
Hoffman, who married second wife businesswoman Lisa Hoffman in 1980, won best actor Oscars for Kramer vs Kramer in 1980 and in 1989 for Rain Man.
He has been nominated for 13 Golden Globes, winning six, won four BAFTAs and two Emmys.