Uccello does not seem to have maintained a large studio. Only a single individual, Antonio di Papi, is recorded as an assistant, in the documents for work carried out at S Miniato al Monte (Saalman, 1964). On the whole, Uccello's paintings do not show evidence of collaboration. Yet it is clear that a number of painters were influenced by his distinctive style and, accordingly, may have received some training in his workshop. Of those followers, the Prato Master is perhaps the most individual. His animated style and light tonality are best displayed in the scenes from the Lives of the Virgin and St Stephen (Prato Cathedral) or the Virgin and Child (Dublin, N.G.).

Pope-Hennessy (1950) assigned this name to an anonymous artist closely allied with Paolo Uccello. In collaboration with another artist, he painted the frescoes in the chapel of the Assunta, Prato Cathedral.

Specifically attributed to the Prato Master are the scenes depicting the Birth of the Virgin, the Presentation of the Virgin, the Dispute of St Stephen, most of the figures in the borders surrounding the scenes, images of the Virtues on the ceiling and some of the saints on the entrance arch. The fresco of the full-length figure of Jacopone da Todi, discovered in 1871 behind a Baroque altar in the same chapel, can also be attributed to him.

Pope-Hennessy attributed the frescoes to an artist trained in Uccello's workshop. They would have been painted after Uccello's clockface of 1443 (Florence Cathedral), since the Prato Master borrowed the heads in it as prototypes for his own work. Because the upper frescoes would have almost certainly been painted first, the death of Andrea di Giusto (1450) provides a terminus ante quem for the entire fresco cycle.

The frescoes display several peculiar qualities. The exaggerated facial expressions in the Dispute almost, though perhaps unintentionally, caricature Uccello's interest in physiognomy as a scientific subject. The artist's shifting attention between decorative line and plastic effect is notable. Unsystematic perspective, inexactly constructed figures and an inconsistent handling of space and volumes all point to an artist who enthusiastically followed the advances being made by his contemporaries but developed none himself.

The Prato Master has at times been identified with the Karlsruhe Master and the Master of the Quarata Predella. Scholarly opinion on the subject is varied and sometimes conflicting.

The connections, if any, among these three masters remain unclear and so, too, does the association of the Prato Master with such works as the Virgin and Child, Santa Monica with Two Children and St George and the Dragon (London, N.G.). While most scholars assign these works to Uccello, perhaps they should be attributed to the still enigmatic Prato Master.