The aim of this work is to study the toxic effect of xylene and validate the protective effect of an aqueous extract of date seeds "Phoenix dactylifera L" on the thyroid gland and liver in Wistar Albino rats. The study was conducted in the laboratory on 15 rats, which were divided into three groups: the first group was considered the control, the second group received 1.2 ml/kg/day of xylene daily for 25 days, and the third group received 1.2 ml/kg/day of xylene and was treated with 300 mg/kg/day of Ghars date pit extract for 25 days. The results obtained in the present study show that treatment with xylene induces xylene overload, a decrease in FT4 and FT3 hormones with an increase in TSH and hyperglycemia, as well as an increase in bilirubin, and the activity of transaminases (TGO,TGP), and alkaline phosphatase, indicating that xylene induces liver function disturbances. Moreover, the histological study results show the presence of inflammation in the liver and hepatic necrosis induced by oxidative stress. However, oral administration of the date pit extract from cultivar caused a decrease in the toxic effect of xylene.