The differences in average blood lead levels (PbB) between iron-deficient children of both gypsy and Caucasian origin were determined. PbB were assayed in 89 iron-deficient children (Group ID): 25 gypsies and 64 Caucasians. Two sub-groups were established: sub-group ID1, 57 iron-deficient children without anaemia (11 gypsies, 46 Caucasians), and sub-group ID2, 32 children with iron deficiency anaemia (14 gypsies; 18 Caucasians). Group IS composed of 41 iron-sufficient children (11 gypsies and 30 Caucasians) served as controls. Blood counts, red-cell indices, serum iron concentrations, serum ferritin, and PbB were determined for the entire study population. The average PbB for gypsy and Caucasian iron-deficient children, were 14.25 and 7.25 micrograms/dl (P < 0.01) respectively. The prevalence of iron-deficient children with toxic PbB (> 20 micrograms/dl) was higher in gypsies (24%) than in Caucasians (1.5%) (P < 0.01). A difference in average PbB between the two ethnic groups was also seen in children with normal iron metabolism (average PbB, 10.23 vs 5.65 micrograms/dl for gypsies and Caucasians, respectively, P < 0.001). CONCLUSION Gypsy children should be considered as a population group at risk of lead poisoning in our environment.