Sakowicz is known for his diary, published decades later under the title ''Ponary Diary, 1941-1943: A Bystander's Account of a Mass Murder'' (). It was first published in Poland in 1999 and thereafter translated into several languages: Hebrew in 2000; This diary is reconstructed from writings that Sakowicz had buried in empty lemonade whose family perished in the massacre, and who was at that time a director of the historical division of the
Jewish State Museum of Lithuania. The foreword of the English edition noted that it "is one of the most shocking documents of its time", describing the murder of tens of thousands. She also speculated that "historians were denied access to the diary for many years, possibly because it provides evidence of the atrocities committed by the Lithuanians", and noted that some early transcriptions of the diary fragments published in Lithuania were imprecisely translated "apparently in order to diminish the role played by Lithuanian nationalists in the extermination of the Jews". Waldemar Franciszek Wilczewski likewise suggested that the fact that the last part of Sakowicz diary is missing might be the result of its destruction by Lithuanian perpetrators and collaborators, whose names and identities by that time Sakowicz was aware of, and might have recorded in that part of his diary.
François Guesnet reviewed the book for
Zeitschrift für Ostmitteleuropa-Forschung in 2003. He noted that "Contrary to all customs, the earlier Polish edition is not mentioned anywhere [in the later Hebrew edition, which is nearly identical and clearly based on it], which can certainly be seen as a significant gesture in the shaping of
historical memory". == Ponary Diary editions ==