2-Hy-droxy-methyl-1,3-dimethyl-1H-imidazol-3-ium triiodide.

The crystal packing of the title salt, C6H11N2O+·I3−, can be described as consisting of alternating layers of cations and anions parallel to the (100) plane along the a-axis direction. The components are linked by O—H⋯I, C—H⋯I and C—H⋯O interactions, generating a three-dimensional network. The O atom deviates from the imidazol ring by 0.896 (2) A.