Abstract: Objective To evaluate the effectiveness of combined use of propofol and ketamine for total intravenous anesthesia (TIVA) in adults and to determine their optimal doses. Methods 100 adults with general anesthesia were randomly divided into five groups 〔K0, K0.5, K1, K1.5 and K2, with 0, 0.5, 1, 1.5 and 2 mg/(kg·h) ketamine, respectively〕. The dose of propofol administered during surgery and hemodynamics, respiratory recovery time, awakening time, steward score of recovery and adverse reactions of the patients were recorded. Ten patients from each group were randomly chosen to have plasma concentrations of propofol and ketamine examined. Results The dose of propofol and total price of the two drugs decreased with the increase of dosage of ketamine (P<0.05). Better outcomes in recovery indexes and adverse reactions were observed in Group K1 compared with those in Group K1.5 and K2 (P<0.05). Plasma concentrations of ketamine in Group K1, K1.5 and K2 were higher than those in Group K0.5 (P<0.05). Regression analyses showed a positive correlation between ‘dose of ketamine and operation time’ and ‘respiratory recovery time and awakening time’ and a negative correlation between ‘dose of ketamine and operation time’ and ‘steward score of recovery’. ‘Dose of ketamine’ was also associated with dreams, asleep after awakening, nystagmus and visual changes. The dose ratio of ketamine and propofol was associated with dizzy and adverse reactions. Conclusion Continuous pump infusion of 1 mg/(kg·h) ketamine for TIVA in adults can reduce dosage of propofol and minimize adverse effects of ketamine.