The dolphinfish (Coryphaena hippurus) is an economically important fish species in eastern Taiwan. This study examined the feeding habits of dolphinfish using stomach content analysis. Dolphinfish samples were collected monthly at Shinkang fishing port from October 2012 to December 2013 and 375 samples (47.3-142 cm fork length; 1-23 kg) were analyzed. Based on the index of relative importance (IRI), the most important prey species were sand lances (Ammodytidae sp.; IRI=255.53), followed by the flyingfish (Cheilopogons sp.; IRI=231.99), the moonfish (Mene maculata; IRI=192.7), and Ommastrephidae (IRI=166.7). Other cephalopods were also found in moderate abundance. These results indicated that dolphinfish are an opportunistic predator, feeding predominantly on a few species of pelagic fishes in waters off eastern Taiwan. The feeding habits of the dolphinfish did not differ significantly between sexes. However, stomach content composition changed significantly in dolphinfish >60 cm fork length and among seasons.