Longhi had no children and he is buried in Viggiù, in Lombardy, where he died. Like some of his contemporary competitors, Longhi seems to have suffered from a lack of sociability.
Varriano, John L. (1971). "The Architecture of Martino Longhi the Younger (1602-1660)". The Journal of the Society of Architectural Historians. 30 (2). Journal of the Society of Architectural Historians, Vol. 30, No. 2: 101–118. doi:10.2307/988628. JSTOR988628.