1. A further case of renin-secreting renal juxtaglomerular cell tumour is reported.
2. Hypertension, aldosteronism and hypokalaemia were associated with high peripheral levels of renin.
3. Renin activity was twice as high in right as in left renal vein plasma.
4. A renal juxtaglomerular cell tumour was found in the right kidney and removed, after which the biochemical abnormalities and blood pressure were promptly corrected.
5. Explants of tumour tissue in culture produced large amounts of renin.