The lowliest of the four Chablis appellations with 400ha out of a possible 1800ha under vine. Some argue that the Portlandian limestone clay soil here is inferior to the Kimmeridgean version that exists in the superior appellations, but it is more likely that aspect, microclimate and other factors are more important.
There are moves to abolish this appellation and convert it to Chablis as many see it (in the words of Rosemary George MW) as more petty than petit. But this looks unlikely to happen anytime soon. Overall quality here is disappointing, although from a good producer Petit Chablis can be a good value, slightly lighter version of Chablis.