A 30-year-old women developed post-partum thyroiditis associated with post- partum pituitary infarction. Pituitary stimulation tests demonstrated global pituitary deficiency but there was no thyrotropin response to TRH stimulation and free T4 was normal. Associated goiter and high circulating levels of microsomal antibodies led to the diagnosis of post-partum thyroiditis associated with pituitary deficiency. Two cases of this unusual association have been reported. The underlying pathogenesis might involve post-partum immunological rebound and/or hypocorticism-induced immunological disorders.