The paper examines the translation of two passages of Lucretius’s De rerum natura (1.250-261, 1.271-297) made by the eighteen-year-old Niccolò Tommaseo and published in 1838 in his Poetic memoirs. Some reflections by Tommaseo himself on the problem of translation (which until today remained unknown in the specific bibliography) and some verses of the Latin poem of 1869 sent to the Dutch Certamen Hoeufftianum, De rerum concordia atque incrementis, are combined. There is also mention of the Lucretius-Virgil confrontation conducted by Tommaseo in the essay of 1871 Historical, civil and moral concept of Virgil’s poetry.