The paper presents Treelex, a valence lexicon of French adjectives automatically extracted from a treebank. The corpus contains morphological and syntactic annotations but no subcategorisa- tion information is present for adjectives. Due to rich corpus annotations, our extraction method is guided by linguistic knowledge. The obtained lexicon (about 2000 adjectives and 40 frames) has been evaluated against hand-crafted adjec- tival tables described in (Picabia, 1978) and achieved 0.46 F-measure.