ObjectiveTo compare the effect of pretreatment with butorphanol or tramadol for prevention of propofol-induced injection pain by intravenous injection or drip, in order to explore a safe and effective method. MethodsWe chose 150 patients of ASAⅠ-Ⅱundergoing elective surgery between October 2012 and March 2013 in Sichuan Orthopedic Hospital as the study subjects. They were randomly divided into five groups with 30 patients in each group:butorphanol injection and drip group (group BI and group BD), tramadol injection and drip group (group TI and group TD), control group (group C). Five minutes before anesthesia induction, patients in group BI, TI and C were respectively injected with butorphanol 2 mg, tramadol 100 mg, and saline; patients in group BD and TD were respectively injected with butorphanol 2 mg and tramadol 100 mg before receiving propofol (2.5 mg/kg) for 2 minutes. Assessment of pain during injection was done by using a four-point scale. ResultsThe pre-injection pain incidence in group BI and TI was significantly higher than that in group BD, TD and C(P < 0.05), and it was significantly higher in group BI than group TI (P < 0.05). The incidence of propofol injection pain in group BI, BD, TI and TD were significantly lower than that in group C (P < 0.05), and it was the lowest in group BD (P < 0.05) followed by group BI (P < 0.05). The total rate of pain in group BD was only 6.67%, significantly lower than other groups (P < 0.05). ConclusionsThe pretreatment with butorphanol and tramadol by intravenous injection or drip can reduce the incidence of propofol injection pain. Pretreatment with butorphanol at 2 mg by intravenous drip is more effective, but should be closely observed to avoid adverse events.