We concurrently sampled larvae (2.15-9.45 mm) of the weakfishCynoscion regalisand their potential prey in Delaware Bay during the 1986 and 1987 spawning seasons. Gut content analysis revealed that larval weakfish fed primarily on copepods (41% of diet by dry weight), larvae of the polychaetePolydora ligni(34%), and pelagic invertebrate eggs (14%). As larval weakfish grew, their diet changed from several small prey types to a few larger ones. Mean abundance of prey occurring with larvae smaller than 5.55 mm notochord length was 172.3 μg/L compared with 166.1 μg/L for prey occurring with larvae 5.55 mm and larger. Prey abundance around these means varied up to 1,000 times for small larvae and 100 times for large larvae. Comparison of these results with laboratory work suggests that prey abundance encountered by weakfish larvae less than 5.55 mm in Delaware Bay ranges over scales that can cause large variations in larval growth and survival.