The synthesis of dl-tyrosine labeled with C14 in the [beta] position has been accomplished. The yield was 177 mg. from 1.03 g. of BaCO3. This is a yield of 19%, based on BaCO3. The Grignard carbonation gave yields as high as 89% in trial runs. The specific activity of the tyrosine was 0.9 microcurie/mg. Formulae and equations summarizing the synthesis are presented.