Acres of Skin: Human Experiments at Holmesburg Prison is a 1998 book by Allen M. Hornblum, published by Routledge, ISBN 0-415-91990-8. The book documents clinical non-therapeutic medical experiments on prison inmates at Holmesburg Prison in Philadelphia from 1951 to 1974, conducted under the direction of dermatologist Albert Kligman. The title of the book is a reference to Kligman's reaction on seeing hundreds of prisoners when he entered the prison: "All I saw before me were acres of skin" ... "It was like a farmer seeing a fertile field for the first time".
The publication of Acres of Skin in 1998 attracted considerable international media interest. The book has been reviewed in several journals including the International Journal of Dermatology, Social History of Medicine and Canadian Journal of History.