I established reference values for weight, hematology, and serum chemistry for seven species of free-ranging Hawaiian tropical pelagic seabirds comprising three orders (Procellariiformes, Pelecaniformes, Charadriiformes) and six families (Procellariidae, Phaethontidae, Diomedeidae, Sulidae, Fregatidae, and Laridae). Species examined included 84 Hawaiian dark-rumped petrels (Pterodoma phaeopygia), 90 wedge-tailed shearwaters (Puffinus pacificus), 151 Laysan albatrosses (Diomedea immutabilis), 69 red-footed boobies (Sula sula), 154 red-tailed tropicbirds (Phaeton rubricauda), 90 great frigatebirds (Fregata minor), and 72 sooty terns (Sterna fuscata). Hematocrit, total plasma solids, total and differential white cell counts, serum glucose, calcium, phosphorus, uric acid, total protein, albumin, globulin, aspartate aminotransferase and creatinine phosphokinase were analyzed. Among and within species, hematology and chemistry values varied with age, sex, season, and island of collection. Despite this variation, order-wide trends were observed.