Disclosed are imidazopyrrolidinone compounds of formula (I), wherein the substituents are as defined in the specification. Also disclosed are, pharmaceutical preparations comprising such compounds, uses and methods of use for such compounds in the treatment of a disorder or a disease mediated by the activity of MDM2 and/or MDM4 such as cancer. Examples of a compound of formula (I) are: 5-(5-Chloro-2-methyl-phenyl)-6-(4-chloro-2-methyl-phenyl)-2-(5-fluoro-2-methoxy-phenyl)-1-isopropyl-4-oxo-5,6,-dihydro-1H-pyrrolo[3,4-d]imidazol-4-one 3-[5-(5-Chloro-2-methyl-phenyl)-6-(4-chloro-2-methyl-phenyl)-1-isopropyl-4-oxo-1,4,5,6-tetrahydro-pyrrolo[3,4-d]imidaol-2-yl]-4-methoxy-benzonitrile 6-(4-Chloro-phenyl)-2-(2,4-dimethoxy-pyrimidin-5-yl)-5-(2,6-dimethyl-pyrimidin-4-yl)-1-isopropyl-5,6-dihydro-1H-pyrrolo[3,4-d]imidazol-4-one
