The solution structures of the two self-complementary oligonucleotides, d(AATTTGCAAATT)2 and d(GAGAAGCTTCTC)2, were solved by using torsion angle dynamics and restrained energy minimization. Proton–proton distance constraints were derived from NOE cross-peak volumes using a combination of relaxation matrix analysis and torsion angle dynamics. The final structures allow the recalculation of experimental NOE intensities with satisfactory agreement. The resulting families of conformers were energy minimized to include electrostatic energy terms and to remove some van der Waals clashes remaining at the end of torsion angle dynamics calculations. Both structures showed a conformation close to B-form DNA, as shown by the similarity between their helix parameters and those of standard B-DNA. The latter parameters also give an indication of the reliability of the present structure calculation approach. Copyright © 1999 John Wiley & Sons, Ltd.