One-day-old herring gulls (Larus argentatus) were injected intraperitoneally with lead nitrate solution (0.1 or 0.2 mg Pb/g) or sterile saline to examine differences in growth rates. Despite the low levels of lead exposure, by d 8 there were significant differences in growth rates as a function of treatment. There were also, by d 8, significant differences in bill length, tarsus length, and wing bone length. Except for bill length, these differences persisted for the duration of the study. Developmental curves varied, with lead-treated birds reaching the same asymptote as control birds for bill length, but having a lower asymptote for tarsus length. For curves where asymptotes were reached, lead-treated birds required more days to reach it than control birds. The initial amount of food eaten each day was positively correlated with weight gain for control birds, but negatively correlated for lead-treated birds.