Résumé : This paper summarizes the present status of the researches conducted with [18F]4-(2'-methoxyphenyl)-1-[2'-[N-(2''-pyridinyl)-p- fluorobenzamido]ethyl]-piperazine known as [18F]p-MPPF, a new 5-HT(1A) antagonist for the study of the serotonergic neurotransmission with positron emission tomography (PET). This includes chemistry, radiochemistry, animal data (rats, cats, and monkeys) with autoradiography and PET, human data with PET, toxicity, and metabolism. (C) 2000 Elsevier Science Inc.