The need for establishing physiologic values for a species was recognized and the many variables affecting these must be considered. The physiologic value differences and similarities between captive and wild bighorn sheep (Ovis canadensis) was discussed from values obtained from 71 captive and 65 wild bighorns. Similar values between captive and wild sheep occurred with; calcium, blood urea nitrogen, cholesterol, packed cell volume, total protein, albumin, total globulin, alpha globulin, beta globulin, gamma globulin, albumin/globulin ratio, magnesium and hemoglobin. Dissimilarity occurred with; phosphorus, calcium/phosphorus ratio, serum glutamic oxalacetic transaminase, glucose, and rectal temperature values. Other variables potentially influencing these values were recognized and the difficulty of separating some variables from the wild/captive classification was discussed.