The major aim of the Szeged Treebank project was to create a high-quality database of syntactic structures for Hungarian that can serve as a golden standard to further research in linguistics and computational language processing. The treebank currently contains full syntactic parsing of about 82,000 sentences, which is the result of accurate manual annotation. Current paper describes the linguistic theory as well as the actual method used in the annotation process. In addition, the application of the treebank for the training of automated syntactic parsers is also presented.