Although reasonably strong support has been obtained for the Five Factor Model's (FFM) ability to account for the existing personality disorder (PD) constructs, the support for obsessive-compulsive PD (OCPD) and dependent PD (DPD) have been relatively less consistent. Specifically, the expected correlation between OCPD and the FFM trait of conscientiousness has varied in magnitude across studies while DPD has, at times, also evinced rather weak relationships with FFM agreeableness. We determined that these inconsistencies were due primarily to the reliance on FFM measures that lack adequate fidelity to assess the maladaptive aspects of high conscientiousness and agreeableness. When alternative measures were utilized, the correlations were generally large and in line with expectations. We conclude that OCPD and DPD can be fruitfully conceptualized within the FFM, but encourage the use of measures that do provide a comprehensive assessment of both the adaptive and maladaptive aspects of the FFM traits.