A variant of two-dimensional nuclear Overhauser effect spectroscopy (NOESY) is described which allows one to observe cross-relaxation pathways between protons that have heteronuclear scalar couplings to nitrogen-15 or carbon-13 nuclei. In 15N-enriched proteins, it is possible to focus attention on Overhauser effects between amide protons. All Overhauser effects between amide and other protons are eliminated by inserting a bilinear rotation decoupling (BIRD) sequence in the middle of the relaxation interval. The mechanism of the suppression of cross relaxation is analogous to expts. involving selective inversion of the longitudinal magnetization of protons under investigation by quenching undesirable indirect external trouble in nuclear Overhauser effect spectroscopy (QUIET-NOESY). The new method is therefore called QUIET-BIRD-NOESY. [on SciFinder (R)]