The stereoselectivity in the formation of crystalline inclusion complexes (IC) of poly(3-hydroxybutyrates)s (PHB) with cyclodextrins (CD) was discussed. It was observed that a-PHB was not able to form ICs with α- or β- CDs. The analysis suggested that the α- or β-CD cavity was too small to accomodate the a-PHB chain in low-energy extended conformations necessary for inclusion.