The current study evaluates the measurement precision of the Abridged Big Five Circumplex (AB5C) of personality traits by identifying those items that demonstrate differential item functioning by gender and ethnicity. Differential item functioning is found in 33 of 45 (73%) of the AB5C scales, across gender and ethnic groups (Caucasian vs. African American). More differential item functioning is found by ethnic groups compared with gender groups. The amount of differential item functioning found in these personality measures suggests the need to consider differential item functioning in the construction of measures. The authors encourage those using the AB5C measure to discard or reword these problematic items. (Contains 1 figure and 6 tables.)