In 1945 Pier Antonio Quarantotti Gambini was the director of Trieste Municipal Library and an already a well-known writer. He witnessed the forty days’ military occupation of Trieste by the army of marshal Tito and the following establishment of the Allied Military Government. The writer was intensely engaged with the writing of his journal of those day that could only be published in 1951. Some excerpts are presented and aim to show Trieste’s dramatic situation in that significant and crucial historical moment.