The configurational assignments of poly(methacrylonitrile) are derived from double-quantum-filtered phase-sensitive H-1 homonuclear shift-correlation and proton-detected H-1-C-13 heteronuclear shift-correlation NMR spectroscopies. The overlapping peaks for different tacticities in the 1D spectrum have been separated and assigned by 2D methods. Assignments to the methylene region of the H-1 and C-13 spectra have been made to hexad and tetrad levels, respectively. The results indicate that the previous assignments for this system are invalid.