Objective To explore the point-specific clinical effect of 2 Hz electroacupuncture (EA) in treating postoperative pain in patients undergoing total knee arthroplasty (TKA), Methods In a randomised, partially single-blinded preliminary study, 47patients with TKA were randomly divided into three groups: control group (CG, n=17) using only patient-controlled analgesia (PCA); EA group (EAG, n=16) with 2 Hz EA applied at ST36 ( Zusanli) and GB34 ( Yanglingquan) contralateral to the operated leg for 30 min on the first two postoperative days, also receiving PCA; and non-point group (NPG, n=14), with EA identical to the EAG except given 1 cm lateral to both ST36 and GB34. The Mann–Whitney test was used to show the difference between two groups and the Kruskal–Wallis test to show the difference between the three groups. Results The time until patients first required PCA in the CG was 34.1±22.0 min, which was significantly shorter than the 92.0±82.7 min in the EAG (p<0.001) and 90.7±94.8 min in the NPG (p<0.001); there was no difference between the EAG and NPG groups (p>0.05). The total dosage of PCA solution given was 4.6±0.9 mL/kg body weight in the CG, 4.2±1.0 mL/kg in the EAG and 4.5±1.0 mL/kg in the NPG; there were no significant differences (p>0.05) among the three groups. Conclusions In this small preliminary study, EA retarded the first demand for PCA in comparison with no EA. No effect was seen on the total dosage of PCA required and no point-specific effect was seen.