The present study was conducted to evaluate the pharmacological and toxic effects of aqueous acetone extract of Sida alba L. a Malvaceae species, in mice Swiss and albinos Wistar rats. In acute toxicity test, mice received doses of this extract by intraperitoneal route with LD50 value of 3200 mg/kg. In sub-acute toxicity test, albinos Wistar rats were treat by gavage during 28 days with different doses of aqueous acetone extracts of Sida alba L., (75, 100 and 150 mg/kg). About to the pharmacological properties, the results varied widely in dose of extract and weight of rats and did not show clinical correlations. We undertook this study of extracts in order to provide a scientific basis for the traditional use of Sida alba L., in traditional medicine particularly to treat hepatitis B. Our results of this study appeared to show the safety of acute and sub-acute toxicities of extract from Sida alba L., which can therefore be continuously used with safety in traditional medicine. Statistical studies revealed that there is a low significant difference in body and organ weights, and biological parameters between control group and the treated assay groups (p<0.01 or p<0.05)