Background: Cadmium (Cd) is a metal. It causes thyroid toxicity. Objective: To explore the possible protective effects of quercetin (QUE) and phytic acid on Cd induced thyroid toxicity. Materials and Methods: 54 rats divided into two groups. Group I (control), group II subdivided into four subgroups; subgroup IIA (rats were injected s.c with Cd in a dose of 2 mg/kg for 2 weeks), subgroup IIB (rats were injected as subgroup IIA & QUE in a dose of 500 mg/ kg orally for 2weeks), subgroup IIC (rats were injected as subgroup IIA & phytic acid at a dose 360 mg/ kg orally for 2 weeks), subgroup IID (rats were injected with Cd as subgroup IIA & QUE as subgroup IIB & phytic acid as subgroup IIC).Thyroid gland specimens were taken and prepared for histological, immunohistochemical examination. Results: Subgroup IIA disorganized folliclluar cells with small dark nuclei,fused follicles with desqumation of cells, significant marked increase(p< 0.01) in collagen fibres and PCNA between follicles and significant decrease(p>0.01)in colloid. Subgroups IIB and IIC showed improvement of some histological microscopic changes, significant decrease (P