Cyclodextrins (CDs) were found to form inclusion complexes with aliphatic polyesters [-O(CH2)(x)OCO(CH2)(4)CO](n) (where x = 2, 3, or 4) to give crystalline compounds. alpha- and gamma-CD formed complexes with these polyesters in high yields, although beta-CD gave complexes in moderate yields. Although the yields of the complexes of alpha-CD with poly(trimethylene adipate) (PTA) (x = 3) and poly(1,4-butylene adipate) (PEA) (x = 4) decreased with increasing molecular weight, alpha-CD formed complexes with poly(ethylene adipate) (PEA) (x = 2) in high yields even at higher molecular weights. The yields of the complexes of gamma-CD with these polyesters showed. a maximum at the molecular weight of 1000. The complexes were isolated and characterized by FTIR, H-1 NMR, C-13 CP/MAS NMR spectra, and X-ray diffraction studies. The inclusion modes are discussed.