We examined several determinants of interjudge agreement on personality traits. The findings, which were cross-validated in two samples, suggest that agreement is a function of four factors: which Big Five content domain the trait represents, how observable relevant behaviors are, how evaluative the trait is, and whether the self is one of the judges. Agreement was highest for traits related to Extraversion and lowest for traits related to Agreeableness. More observable and less evaluative traits elicited higher interjudge agreement. On average, self-peer agreement was lower than peer-peer agreement. However, this effect was limited to evaluative traits; for neutral traits, self-peer agreement was as high as peer-peer agreement. These findings suggest that self- and peer perception proceed through similar processes for neutral traits but not for highly evaluative traits, raising the possibility that self-perceptions become distorted when the trait is affectively charged.