AbstractWe present a new method for recording broadband proton‐decoupled proton spectra with absorption mode lineshapes and substantially correct integrals; in both these respects, the new method has significant advantages over conventional J‐spectroscopy. In our approach, the decoupled spectrum is simply obtained from the 45° projection of the diagonal‐peak multiplets of an anti z‐COSY spectrum. This method is straightforward to apply, and does not require any unusual data processing. However, there is a significant reduction in sensitivity when compared to a conventional proton spectrum. The method is demonstrated for typical medium‐sized molecules, and it is also shown how such a decoupled spectrum can be used to advantage in measurements of diffusion constants (DOSY), the measurement of relaxation parameters, and the analysis of complex mixtures. Copyright © 2007 John Wiley & Sons, Ltd.