Baseline blood biochemistry values were obtained for two foraging aggregations of clinically healthy wild, juvenile green turtles (Chelonia mydas) inhabiting Kaneohe Bay, Island of Oahu, and the Kona Coast, Island of Hawaii. Mean reference values were compared to values obtained from green turtles of similar size affected with fibropapillomas (FP) collected at Kaneohe Bay. Statistically significant differences were identified for total protein values, blood urea nitrogen, and enzyme values between healthy turtles and turtles with FP. In addition, turtles with severe FP were hypoproteinaemic, hypoalbuminaemic, hypoferraemic, azotaemic, and presented inverse calcium/phosphorus ratios, low cholesterol and triglyceride values, indicating the chronicity and severity of FP. It is concluded that blood reference values should be established for green turtles at the population level and by geographic area considering disease status, age, sex, and seasonal variations.