A method is developed for the determination of interproton distances from homonuclear NOESY-NOESY spectra using a complete relaxation rate matrix approach. The effect of experimental random noise and integration errors on the resultant distances was investigated. The dependence on the initial model was also examined. The procedure used to symmetrize the 2D intensities deconvoluted from 3D intensities may also be used for the correction of partial relaxation of a 2D NOE intensity matrix. Part of the program was developed on Computer Graphics Laboratory computers. MidasPlus has been used to visualize the structures, and color pictures made using MidasPlus were used for publication of the results.