(E)-5-[hydroxyimino(phenyl)methyl]-1-methyl-3-4-dihydro-2H-pyrrolium trifluoromethanesulfonate.

The cation of the title compound, C12H15N2O+*CF3SO3-, exists as an E-configured hydroxyimino derivative conjugated with a nearly planar iminium system. The twist angle between the phenyl ring and the oxime group is 72.2 (2) degrees. An O--H...O hydrogen bond links the oxime group of the cation to the anion.