Rheooptical FTIR spectroscopy provided a detailed picture of hard- and soft-segment orientation during cyclic loading-unloading of elastomeric poly(tetramethylene glycol)-carboxy-terminated poly(azacyclotridecan-2-one) block copolymer. The soft segments of the polyamide-polyester-polyoxyalkylene showed pos. chain alignment during loading and chain disorientation during unloading. Deformation of the hard segments was characterized by an initial transverse orientation with a subsequent morphol. reorganization.