Serum zinc level in cord blood of 159 neonates was estimated by atomic absorption spectrophotometer. The cases were classified according to birth weight and gestation of babies as Term appropriate for date (TAFD), Term small for date (TSFD), Term large for date (TLFD), Preterm appropriate for date (PAFD), Preterm small for date (PSFD) and Preterm large for date (PLFD). The zinc level were also estimated in mothers of these groups at the time of delivery, and compared with cord blood levels of those in non-pregnant mothers. Mean serum zinc level in infant born full term AFD, full term SFD, full term LFD, preterm AFD, preterm SFD and preterm LFD were 79.6 +/- 17.8 micrograms/dl, 58.2 +/- 13.4 micrograms/dl, 84.1 +/- 21.1 micrograms/dl, 81 +/- 25.2 micrograms/dl, 51.2 +/- 51.7 micrograms/dl and 76 +/- 14.7 micrograms/dl respectively. The maternal zinc levels in respective groups were 67 +/- 9.6 micrograms/dl, 56.5 +/- 7.5 micrograms/dl, 63.6 +/- 14.4 micrograms/dl, 62.7 +/- 21.1 micrograms/dl, 54.5 +/- 5.4 micrograms/dl, and 58.2 +/- 2.7 micrograms/dl. The mean serum zinc values in mothers and babies in birth weight group ranging from 1500-2000 gm were 55.3 +/- 4.3 micrograms/dl and 60 +/- 23.1 micrograms/dl, 2001-2500 gm were 59.5 +/- 11.3 and 65.8 +/- 17 micrograms/dl, 2501-3000 gm were 69.2 +/- 9.5 and 84.7 +/- 14 micrograms/dl, 3001-3500 gm were 65.8 +/- 12.7 micrograms/dl, 82.2 +/- 20.8 micrograms/dl and 3501 and above were 70.5 +/- 8.2 micrograms/dl and 85 +/- 14.3 micrograms/dl respectively. Statistically significant low zinc levels were observed in SFD babies and their mothers.(ABSTRACT TRUNCATED AT 250 WORDS)