The complex beta-cyclodextrin-1,7-dioxaspiro[5,5]undecane nonahydrate, C42H70O35.C9H16O2.9H2O, belongs to the class of beta-cyclodextrin dimeric-type complexes. The racemic guest molecule is present in a disordered position. Both enantiomers are located in two different regions inside the channel formed by the host dimers.