Born into a family of artists, Giovanni applied himself mostly to genre painting, and especially to scenes with flowers and musical instruments. He also provided the decoration for theatrical scenery, in a manner similar to Mario Nuzzi (Mario dei Fiori), although with a greater penchant for Flemish elements.
In 1638, he sold to the Barberini a painting with a garland of flowers and their coat of arms, and was subsequently employed by the most important families in Rome. He was commissioned by Cardinal Flavio Chigi to adorn a gallery with flowers and fruits, in collaboration with Baciccio, and he also painted mirrors. Cardinal Benedetto Pamphili was his patron for the decoration of painted stage scenery, harpsichords and spinets.
Giovanni Stanchi's known surviving works are few in number, and are all to be found in Rome: two still life paintings with flowers and dead game (Galleria Pallavicini), a pair of overdoors with flowers and birds formerly in the Sacchetti Collection (now in the Pinacoteca Capitolina), and the decoration of lunettes with festoons of flowers in the Palazzo Colonna.