Sida rhombifolia L. is used as a remedy for inflammatory disorde and some other diseases in African folk medicine. The present study was conducted to evaluate the haematological and biochemical parameters and toxic effects of aqueous acetone extracts of Sida rhombifolia L. in mice Swiss and albinos Wistar rats. Sida rhombifolia L. is used as a remedy for inflammatory disorde and some other diseases in African folk medicine. In an acute toxicity study, Sida rhombifolia extract was administered orally at doses ranging between 1-6 g/kg to experimental mice and observed for any toxic symptoms up to 14 days. In sub-acute toxicity, Sida rhombifolia extract was tested at dose levels of 100, 200 and 300 mg/kg on physical (body weight and organ weight), biochemical and haemtological parameters in adult albino rats. The Sida rhombifolia extract was well tolerated at the acute administration. No mortality was observed even at the highest dose of 6 g/kg (the value of LD50 is greater than 5000 mg/kg). In the subacute administration, Sida rhombifolia extract significantly (p

Biological parameters, LD50, mice, Sida rhombifolia L., toxicity, wistar rats