To determine the personality characteristics associated with affective disorders the authors administered a battery of self-report personality inventories to a sample of hospitalized affective patients when their manifest symptoms had abated. Patients were instructed to answer according to their premorbid personalities. The personality characteristics assessed in the 73 depressive and 24 manic patients included neuroticism and extraversion from the Maudsley Personality Inventory, obsessional pattern, hysterical pattern, and oral pattern from the Lazare-Klerman-Armor Personality Inventory, obsessional state and trait from the Leyton Obsessionality Inventory, and solidity, stability, and validity from the Marke-Nyman Temperament Survey. Depressive patients demonstrated more neuroticism, introversion, and obsessionality than manic patients or normal individuals. The manic patients differed from normal persons only on obsessionality.