Kosinski is perhaps best known for his novels The Painted Bird and Being There. The Painted Bird has been implied to be based on his experiences during World War II. However it is now widely considered that the events depicted were fictional: that Kosinski did not for example wander the countryside of Eastern Europe during the war. The book rather shows his unfriendly feelings toward peasants and his complete ignorance about their life. He describes them using the same paint as anti-semitic books described Jews. Being There was later made into a movie directed by Hal Ashby and starring Peter Sellers.
Towards the end of his life, Kosinski was accused of plagiarism - of taking much of his work from Polish sources with which English speakers were unfamiliar (For example, Being There, for any Polish reader, bears much resemblance to Kariera Nikodema Dyzmy, the Polish bestseller by Tadeusz Dołęga-Mostowicz, widely known in Poland); and also of having his "assistant editors" write much of his work without receiving credit. The critics making these charges often point to the wild differences in the styles of prose from one novel to the next. They however neglect the stylistic differences apparent in the work of almost any artist who has produced work for more than a few years. Kosinski responded by writing The Hermit of 69th Street (1988), an attempt to show the absurdity of noting all prior art by inserting footnotes for practically every term in the book.
Criticisms arose, when the public was confronted with the real picture of the life of Kosinski during the Holocaust time, as described in the book by Joanna Siedlecka. She has shown that his life was diametrically different to what was described in The painted Bird. Jerzy Kosinski never showed any gratitude towards those who helped him survive the war.
Kosinski committed suicide on May 3, 1991. Tabloid publications widely reported that his death was the result of autoerotic asphyxiation, but this was dismissed in the coroner's report which observed that his parting note read "I am going to put myself to sleep now for a bit longer than usual. Call the time Eternity."(quote from Newsweek, May 13, 1991).