Introduction: The diagnosis of post-trauma pituitary stalk transection, which is often life-threatening condition, is frequently delayed. In medical literature still exist conflicting data concerning distinguishing this pathology with genetic developmental pituitary stalk interruption syndrome (PSIS). Case presentation: We present a case of patient with post-trauma pituitary stalk transection resulting in combined life-threatening pituitary hormone deficiency (CPHD) and typical MRI picture: atrophic not visible stalk and posterior pituitary and hypotrophic anterior pituitary with most typical for this disorders hyperintense signal of distal regenerating axon of hypothalamus (pseudo posterior lobe) at median eminence with not visible posterior pituitary. This latter finding is often confused with ectopic posterior lobe in genetically determined PSIS. Conclusions: MRI image together with medical history of the head trauma and its strict temporal relation with transient diabetes insipidus and the occurrence of CPHD signs, as well as the lack of extrapituitary midline defects differentiate posttraumatic pituitary stalk transection syndrome (PSTS) from genetic PSIS. In every case of severe traumatic head injury hormonal evaluation and MRI of hypothalamic-pituitary axis should be performed.