Twenty-two weeks old Babcock layer chickens (324) were randomly allocated to 9 treatment groups with 3 replicates of 12 birds in each to study and compare the effect of Cr from three sources (inorganic, organic or nano) at two different dosage level on performance, mineral retention and tissue mineral accumulation in layer chickens. The trial lasted for 12 weeks. The control group (T1) was given with the standard layer diet while the other groups were supplemented with Cr at 200 µg/kg (inorganic Cr chloride-T2, organic CrProp-T4, CrPic-T6 and nanoCr-T8) and 400 µg/kg (inorganic Cr chloride-T3, organic CrProp-T5, CrPic-T7 and nanoCr-T9) diets. Neither the source nor the level of Cr supplement had significant effect on body weight, feed consumption, egg production and egg weight during the study period. The organic and nanoCr supplementation significantly (P<0.05) increased the retention of Cr, Zn, Fe, Ca and P without influencing Cu retention. NanoCr and organic CrPic/CrProp (400 µg/kg) increased the concentration of Cr and Zn in plasma, liver and egg shell, Ca in liver and egg shell and Zn in egg

yolk. It may be concluded that organic or nanoCr supplementation (400µg/kg) in the diet improved the retention and tissue accumulation of minerals in layer chickens.