PSGL-1, a specific ligand for P-, E- and L-selectin, was isolated from in vivo [3H]-glucosamine labeled HL-60 cells by a combination of wheat germ agglutinin-agarose and P- or E-selectin-agarose chromatography. N-linked oligosaccharides were released from the purified, denatured ligand molecule by peptide: N-glycosidase F treatment and, following separation by Sephacryl S-200 chromatography, partially characterized using lectin, ion-exchange and size-exclusion chromatography in combination with glycosidase digestions. The data obtained suggest that the N-glycans on PSGL-1 are predominantly core-fucosylated, multiantennary complex type structures with extended, poly-N-acetyllactosamine containing outer chains. A portion of the outer chains appears to be substituted with fucose indicating that the N-glycans, in addition to the O-glycans on PSGL-1, may be involved in selectin binding.