This study was conducted to investigate the effects of various levels of nanoparticles chromium picolinate on performance, egg quality, minerals retention, and tissues accumulation of layer chickens. This study used 54 seventy-week old post-molt laying hens randomly allocated into 0 (control), 500 ppb (µg kg -1 ) Cr and 3000 ppb Cr groups for a 60-day experiment. The chromium was nanosize (80.8 ± 2.7 nm) chromium picolinate (NanoCrPic) and each treatment was undertaken with six replicates. In the meantime, a total of 18 birds (1 bird/replicate) were used for metabolic experimentation. The results of the experiment indicated that there were no significant effects on body weight, feed intake, feed efficiency, and egg production of layers. Supplemental NanoCrPic could significantly (p < 0.05) improve egg quality, or retention of chromium and zinc, but decrease shell ratio in the 60 th day eggs. The addition of NanoCrPic resulted in increased minerals accumulation in tissues such as Cr, Ca, and P concentration in the liver, Cr concentration in the yolk and Ca concentration in the eggshell. In conclusion, supplemental NanoCrPic improved Cr and Ca accumulation in the liver and egg, improved Zn and Mn retention in layer chickens.