The harm avoidance (HA) personality dimension has been hypothesized to be a vulnerability factor for unipolar depression (UD) but not for bipolar disorder (BD). The reported difference on HA scores between these diagnostic groups may have been compromised by the assessment of BD patients who had not fully recovered. To test the diagnostic specificity of elevated HA scores and to elucidate whether assumptions about differences between patients with UD or BD might be attributed to the lingering effects of mood state, the Tridimensional Personality Questionnaire (TPQ) was administered to recovered patients with either BD or UD and a nonpatient comparison group. Both patient groups scored higher on the HA dimension than the nonpatient comparison group, but the patient groups did not differ from one another on this dimension. Moreover, novelty seeking (NS) scores were elevated in subjects with BD compared with both UD patients and nonpatient subjects. These results suggest that high HA scores may be associated with a mood disorder diagnosis, whereas high NS scores may be associated with the BD subtype.