The Formosan sika deer (Cervus nippon taiouanus) is an endemic subspecies in Taiwan. The original wilddeer has been extinct since the late 1960s. The largest captive population is located at the Taipei Zoo. Except forinfectious disease outbreaks, no systemic medical research has been reported for this subspecies. This study wasconducted to analyze the medical status of the captive Formosan sika deer population, including the hematologicaland serum chemistry characteristics. To accomplish this, medical records for 34 Formosan sika deer from January2003 to January 2014 were acquired and analyzed. The most common illness and cause of death was trauma, followedby gastrointestinal and respiratory disease, respectively. The hematologic and serum chemical values of healthy adultswere quite different from those of sika deer (Cervus nippon yesoensis). This study provides a closer medicalunderstanding of this subspecies and the results will facilitate its management.Keywords : Formosan sika deer, gastrointestinal disease, respiratory disease, Taiwan, trauma