A high-resolution triple-resonance NMR method is presented for the measurement of the protein backbone dihedral angle psi based on cross-correlated relaxation between H-1(alpha)-C-13(alpha) dipolar and C-13' (carbonyl) chemical shift anisotropy relaxation mechanisms. The method relies on measurement of peak intensities of multiplet components in spectra recording zero-and double-quantum C-13(alpha)-C-13' coherences. Results based on two proteins, ubiquitin and CheY, demonstrate a well-defined relation between cross-correlation rate and psi.