An overview of current methods employed for characterizing larger (>25 kDa) proteins by NMR is presented. These techniques include: the attenuation of T2 relaxation effects by offsetting dipole-dipole and chemical shift anisotropy relaxation mechanisms (TROSY); the extraction of residual dipolar couplings from partially oriented molecules; the elimination of relaxation pathways by incorporating deuterium nuclei into protein samples; the easing of resonance overlap by isotopically labeling only specific protein segments; and the decrease of rotational correlation times by dissolving proteins in low viscosity solvents. © 2002 Elsevier Science B.V. All rights reserved.