The extent of segmental motion of the backbone and sidechain carbons of the glycopeptide antibiotic, bleomycin-A2 in aqueous solution, has been determined from the natural abundance carbon-13 spin-lattice relaxation times (T1) measured at 67.89 MHz. The backbone carbons of the central residues have an average T1 of 163 msec, corresponding to an isotropic rotational correlation time of 3.9×10-10 sec. The backbone and sidechain carbons exhibit varying degrees of motional freedom. The solution conformation of bleomycin-A2 is discussed in terms of the conformational flexibility available to these carbons. © 1978 Academic Press, Inc.