Novel 3,4-di-, 3,3,4-di-, 3,4,4,-tri- and 3,3,4,4-tetra-substituted pyrrolidine compounds, these compounds for use in the diagnostic and therapeutic treatment of a warm-blooded animal, especially for the treatment of a disease (=disorder) that depends on inappropriate activity of renin; the use of a compound of that class for the preparation of a pharmaceutical formulation for the treatment of a disease that depends on inappropriate activity of renin; the use of a compound of that class in the treatment of a disease that depends on inappropriate activity of renin; pharmaceutical formulations comprising a said substituted pyrrolidine compound, and/or a method of treatment comprising administering a said substituted pyrrolidine compound, a method for the manufacture of said substituted pyrrolidine compounds, and novel intermediates and partial steps for their synthesis are described. The substituted pyrrolidine compounds are especially of the formula (I) wherein the substituents are as described in the specification. ##STR00001##