In response to multiple peracute deaths caused by herpesvirus in several pheasant species, a study was designed to determine the absorption, distribution, and linearity of acyclovir in hybrid tragopans (Tragopan caboti × Tragopan temminckii). Acyclovir was administered to 5 healthy adult tragopans, 3 males and 2 females, in a single dose of 40, 80, or 120 mg/kg PO. Blood samples were collected at 1, 2, 6, 12, and 24 hours after administration, and concentrations of acyclovir were measured by reverse phase high-performance liquid chromatography (HPLC) with a C-8 column and ultraviolet (UV) detection. Although plasma concentrations were not linear, results from this study suggest that a dosage of 120 mg/kg PO q12h in tragopans may achieve effective plasma concentrations (1.0 μg/ml) for potential treatment and prevention of herpesviral infections. However, further studies are needed to determine if this dosage is safe for repeated administration.