Practical experience is vital for promoting interest in science. Several aspects of chemistry are rarely taught in the secondary school curriculum, especially nuclear and radiochemistry. Therefore, we introduced radiochemistry to secondary school students through positron emission tomography (PET) associated with computer tomography (CT). PET-CT technology, radiochemistry, and clinical practice were introduced through five steps comprising fundamental aspects of nuclear chemistry, organic synthesis, diagnostic nuclear medicine, evaluation of medical results, and final presentation of their exposure through posters and oral presentations.