Transcription factor AP-2beta has been suggested to influence brain monoaminergic systems by regulating target genes. In order to explore a possible functional role, AP-2beta genotype was analysed in relation to striatal dopamine D2 receptor density determined in vivo by positron emission tomography in human subjects (n = 52). The AP-2beta genotype was also analysed in relation to cerebrospinal fluid (CSF) concentrations of homovanillic acid (HVA), 3-methoxy-4-hydroxy-phenylglycol (MHPG) and 5-hydroxyindoleacetic acid (5-HIAA) in healthy human subjects (n = 90). There was no association between the AP-2beta genotype and measures of dopamine receptor density, or CSF 5-HIAA concentrations. However, AP-2beta genotype was associated with CSF-levels of HVA (in women) and MHPG. These data may suggest a functional involvement of AP-2beta in the dopaminergic system, but should be interpreted with caution until replicated.