OBJECTIVE To define the relation between mood, anxiety, puerperal-depression and autoimmune-thyroid-disfunction. METHODS We screened 292 mothers 2 to 3 days after delivery for anxiety, depression and mood disturbances as well as thyroid-function and microsomal antithyroid-antibody status. Ten autoantibody positive woman were compared with an equal number of age-matched controls. The state-trait-anxiety inventory which consists of 20 questions concerning state-anxiety (anxiety in a given situation) and 20 questions concerning trait-anxiety (anxiety as a quality of personality) was used to describe anxiety. The Beck-depression-inventory was applied to measure depressive illness. To assess the mood we used the "Giessener Beschwerdebogen". RESULTS We found subclinical hypothyroidism in 40% of the antibody positive women and their matched pairs. Another 10% of these 20 women showed clinical hypothyroidism. There was no significant association of thyroid-function or disfunction with neither anxiety nor depressive illness or mood disturbance. The incidence of state-anxiety was significantly higher in the antibody positive group than in the antibody negative group (Chi2 = 3,3; P < 0.04). Trait-anxiety showed a tendency to be higher in the antibody positive group, but the difference was not significant (Chi2 = 2; P < 0,08). The frequency of depressive illness or mood disturbance at the time of assessment was not significantly different in thyroid-antibody positive group compared with antibody negative group. CONCLUSIONS Autoantibody induced thyroiditis may contribute to anxiety in the postpartum period.