Positron emission tomography [PET] is a powerful nuclear clinical imaging technique used for the detection and treatment of central nervous system (CNS) disorders, cardiovascular diseases, and certain cancers. Due to the often short half-lives of the radiolabeled compounds employed, the availability of relevant tracers is severely limited. Through the use of microfluidic techniques many of the limitations of conventional synthesis of radiotracers are alleviated, paving the way for diverse families of compounds to be developed with defined targets for imaging. This review will survey syntheses of various radiotracers using new microfluidic techniques being developed.