Substituted fused [1,2]imidazo[4,5-c] ring compounds (e.g., imidazo[4,5-c]quinolines, 6,7,8,9-tetrahydroimidazo[4,5-c]quinolines, imidazo[4,5-c]naphthyridines, and 6,7,8,9-tetrahydroimidazo[4,5-c]naphthyridines) with a —CH(—R1)— group in the fused ring at the 1-position of the imidazo ring, wherein R1 includes a functional group, for example, an amide, sulfonamide, urea, carbamate, ester, ketone, ether, a thio analog of the forgoing, sulfone, oxime, or hydroxylamine, pharmaceutical compositions containing the compounds, intermediates, methods of making the compounds, and methods of use of these compounds as immunomodulators, for inducing cytokine biosynthesis in animals and in the treatment of diseases including viral and neoplastic diseases, are disclosed.