Synodus pacificus sp. nov., a new species of lizardfish, is described based on specimens collected in the western Pacific Ocean. It belongs to a species group with needle-like posterior processes of the pelvic girdle and differs from its congeners by having the following combination of characters: 4 upside-down omega-shaped marks on the lateral body; black patches on the nape and opercular region; cross bars on the ventral surface of the head; bars on the dorsal and caudal fins; orbital large (6.7-8.1% SL); interorbital space narrow (2.1-2.8% SL); snout short (6.3-7.2% SL); anterior palatine teeth not longer than posterior teeth; pectoral fin extending slightly beyond a line from base of pelvic fin to origin of dorsal fin; 7 peritoneal spots; peritoneal membrane pale; nasal flap long and pointed; dorsal-fin rays 11-13 (mainly11); anal-fin rays 9-11 (mainly 10 or 11); pectoral-fin rays 11-14 (mainly 12); total vertebrae 53 or 54; pored lateral-line scales 52-54; transverse scale rows above the lateral line 3.5, below 4.5 or 5; gill rakers 31-37; and 17-29 teeth on free end of tongue.