A 29 year-old female patient developed severe arterial hypertension in the beginning of her second pregnancy. Investigations performed at 16 weeks of amenorrhea showed hypokaliemia in relation to severe hyperreninism: plasma active renin was 25 fold normal value, 94% as prorenin (prorenin representing 94% of total renin). Radiological investigations including ultrasonography and MRI disclosed an homogenous and avascular tumor in the right kidney. Its ablation confirmed renin tumor, and allowed recovery from HTA and continuation of pregnancy. This is the 75th reported case in the literature, enabling to make a new statement about diagnostic and therapeutic procedures, which are modified during pregnancy by contra-indication to X-rays and renin-angiotensin-aldosteron axis inhibitors.