The hawksbill turtle, Eretmochelys imbricata, is a marine chelonian with a circum-global distribution, but the species is critically endangered and has nearly vanished from the eastern Paciﬁc. Although reference blood parameter intervals have been published for many chelonian species and populations, including nesting Atlantic hawksbills, no such baseline biochemical and blood gas values have been reported for wild Paciﬁc hawksbill turtles. Blood samples were drawn from eight hawksbill turtles captured in near shore foraging locations within the Galápagos archipelago over a period of four sequential years; three of these turtles were recaptured and sampled on multiple occasions. Of the eight sea turtles sampled, ﬁve were immature and of unknown sex, and the other three were females. A portable blood analyzer was used to obtain near immediate ﬁeld results for a suite of blood gas and chemistry parameters. Values aﬀected by temperature were corrected in two ways: (i) with standard formulas and (ii) with auto-corrections made by the portable analyzer. A bench top blood chemistry analyzer was used to measure a series of biochemistry parameters from plasma. Standard laboratory haematology techniques were employed for red and white blood cell counts and to determine haematocrit manually, which was compared to the haematocrit values generated by the portable analyzer. The values reported in this study provide reference data that may be useful in comparisons among populations and in detecting changes in health status among Galápagos sea turtles. The ﬁndings might also be helpful in future eﬀorts to demonstrate associations between speciﬁc biochemical parameters and disease or environmental disasters.