BACKGROUND Spontaneous hemorrhage is a rare cause of masses in the adrenal gland and must be differentiated from hemorrhage caused by trauma, neoplasm or metastases. METHODS A 41-year-old pregnant woman presented with nausea and right flank pain. Under suspicion of a pyelonephritis she was referred to the urological department with a normal obstetric evaluation. Ultrasound revealed an inhomogeneous mass above the right kidney, which seemed to be an abscess. An MRI scan showed an adrenal hemorrhage, but a bleeding caused by a neoplasm was excluded by a post-partum MRI control only. Upon conservative therapy the clinical condition improved and the parameters of inflammation normalized. There was no evidence of a hormone-producing adrenal tumor, an adrenal insufficiency caused by the hemorrhage, or a coagulopathy. CONCLUSIONS Spontaneous hemorrhage in the adrenal gland is a rare condition in pregnancy. The diagnosis is confirmed by MRI. If conservative treatment fails, adrenalectomy will be necessary. Adrenal function should be controlled during pregnancy and post-partum. Recurrent hemorrhage and a neoplasm must be excluded by a post-partum MRI.