Cisatracurium is intermediately acting muscle relaxcant, it is threetimes more potent than atracurium, with no histamine release and devoidof cardiovascular side effects.Patients with liver disease exhibit an abnormal response to the effectof most muscle relaxants in the form of increased dose requirements thatwhen administered lasts longer due to delayed elimination. cisatracuriumseems to be favorable exception because of its unique breakdownmechanism. This study was designed to evaluate the dose-response of cisatracuriumin patients with mild to moderate liver impairment in ( ChildA,B) classification comparison to healthy subjects. We used the twodosestechnique of dose response curve described by Meretoja andWirtavouri and modified by Kopman et al. for assessment.The ED50 and ED95 for each group of subjects will be calculated &statistically analysed for each individual, and this will form the doseresponse curve for each individual.In conclusion, there was no effect of liver disease on dose responseto cisatracurium apart from a statistically and clinically significant higherED95 (73.6 μg/kg in the hepatic group versus 50.99 μg/kg in the controlgroup).