The nave is flanked by pilasters that incorporate Ancient Roman marble and granite columns, putatively from the former Temple of Neptune on the Palatine.

The ceiling is colorfully decorated with elaborate framed designs (cassetone) and has a central frescoed panel depicting the Martyrdom of Anastasia (1722) by Michelangelo Cerruti; the work was pursued under the patronage of the Cardinal Nuno da Cunha e Ataíde.

The presbytery was richly decorated in 1705 with marble by the Febei family rebuilt with an endowment of the cardinal Giambattista Costaguti.

The recumbent sculpture of the dying saint, laid atop a flaming pyre, was influenced by Bernini's Beata Ludovica Albertoni.

While the last chapel on the right has a fresco depicting Scenes from the lives of Saints Carlo Borromeo and Filippo Neri by Lazzaro Baldi.

The left transept has a Madonna of the Rosary also by Baldi, and the tomb of Cardinal and philologist Angelo Mai by the late neoclassical sculptor Giovanni Maria Benzoni.