The symphony is the outcome of Mendelssohn's effort to musicalise his experiences from his trip to Italy in 1829-1830. Mendelssohn had then taken a tour to England, Scotland, Wales and Italy and wanted to musically express images, sounds and impressions from these trips. He completed the Italian Symphony a few years after his return to Germany.
The first movement is joyful and energetic, revealing his excitement from his trip to Italy, and having been influenced by the warm mediterranean weather and the extrovertedness and happiness of the people. He wrote in one of his letters: "....there is warmth, mildness and happiness, a sense of joyous well-being spread over everything, that is quite indescribable. My mood is so tranquil and joyous and yet so earnest...I am healthier and happier than I have been for a long time..." Mendelssohn had described this work as the jolliest he had so far written. Musicologists believe that the first movement depicts a lively urban scene from Venice.