The frescoes painted by Pellegrino Tibaldi for the church of Sant'Andrea in Via Flaminia in Rome at the end of 1553 are attested by sources and documents, yet were believed to be irretrievably lost from the time of Giovanni Baglione, who in 1642 described them as ruined following a flood of the Tiber. Following restoration work the original frescoes have astonishingly re-emerged under a layer of repaintings that had transformed their 16th-century appearance. The false niches inhabited by saints constitute not only the sole surviving testimony of Tibaldi's second sojourn in Rome, immediately after his Bolognese work for Giovanni Poggi and before his period in the Marches, but also allow us to appraise his stylistic development at a delicate time of transition towards his practice as an architect.