He suffered from declining health after 1650, and was troubled by a worsening tremor in his hand, evidence of which is apparent in his late drawings. He died in Rome on November 19, 1665 and was buried in the church of San Lorenzo in Lucina, his wife having predeceased him. Chateaubriand in 1820 donated the monument to Poussin.
Poussin left no children, but he adopted as his son Gaspard Dughet (Gasparo Duche), his wife's brother, who became a painter and took the name of Poussin.