The plasma membrane dopamine transporter (DAT) is found exclusively in dopamine neurones and seems to be the defining molecule of the dopamine neurone. It provides effective control over the intensity of dopamine‐mediated signalling by recapturing the neurotransmitter released by presynaptic neurones. Positron emission tomography (PET) and single‐photon emission computed tomography (SPECT) represent unique techniques for assessing in vivo DAT distribution in humans and offer reliable methods for studying nigrostriatal dopaminergic function in health and disease. The characteristics of different DAT radiotracers, the modifying influences of factors such as age, gender, smoking habit, and dopaminergic drugs on DAT transporters as well as their implication in evaluation of neuroimaging studies are discussed. © 2003 Movement Disorder Society