The evaluation of laboratory blood analytes is an important tool for health assessment in avian medicine. Unfortunately, there is a lack of suitable reference values for many zoo bird species. The goal of the present study was to establish reference intervals for a wide range of blood analytes in healthy black-headed ibis (Threskiornis melanocephalus) kept in a zoologic garden. Lithium heparinized blood samples from 15 individuals were collected, and 18 different clinical chemistry analytes were measured. New are especially the minimum and maximum values for bile acid (2.38–49.4 µmol/L), cholinesterase (439–1260 U/L), vitamin A (0.65–1.70 mg/L), vitamin E (26.3–52.5 mg/L), and capillary zone electrophoresis (prealbumin, 10.2–23.4%; albumin, 35.9–44.1%; A/G ratio, 1.07–1.69; α-, 15.7–20.0%; β-, 13.5–19.1%; γ-globulin, 6.08–11.3%). The measured values for clinical chemistry, vitamin, electrophoresis, and hematologic analytes are a basis for further studies and for diagnostics and clinical treatment in this ibis species.