The Oscar-winning actor was found dead in his New York City apartment on February 2.
His mum, Marilyn O'Connor, has released a statement publicly addressing Hoffman's passing for the first time.
Her tribute was read out by the actor's friend, retired film critic Jack Garner, at a film series held at The Little Theatre cinema in Rochester, New York in Hoffman's honour.
The statement read: "It has been a devastating loss for us, but I know that you also feel a great sorrow.
"We miss and cry for the little boy and the man, the brother, the uncle, the husband (sic), the father, the friend, and while we will miss seeing him, we will also miss his talent, his knowledge of his craft, and seeing results of his hard work. He was a gift to me for 46 years. I wanted more.
"My heart is broken and will never be the same again. I know many of you feel the same. We will find our way through this and hear his clear voice and laughter as we do, because he is cheering for all of us to go on, to shine, to be the best that we can be.
"Thank you all and especially, The Little Theatre, a place Phil loved to go and watch movies."
O'Connor's statement was released shortly before coroners revealed that Hoffman had suffered from a fatal mix of heroin, cocaine and prescription drugs. They listed the 46-year-old's cause of death as acute mixed drug intoxication.
The late star, who had three young children with his longtime girlfriend Mimi O'Donnell, was also saluted during a special tribute at the Independent Spirit Awards in Santa Monica on Saturday, when his friend Cate Blanchett honoured Hoffman as "a sublimely talented actor". The Sopranos star James Gandolfini and film critic Roger Ebert were also remembered during the awards show.
All three are expected to be included in the In Memorium segment during the Oscars on Sunday night (Monday AEDT).
