Health education on sexually transmitted infections (STIs), condom use, and partner notification (PN) is required to increase partner evaluation/treatment (PET) rate. To examine this issue, a randomized controlled trial comparing video-based and nurse-led education in women diagnosed with their first STI at the Siriraj Female STI clinic was conducted from March 2015 to March 2017. PN was assessed at two weeks and PET was done at four weeks. Of 330 patients, 225 were included in the analysis (N = 113 and N = 112 for video-based and nurse-led groups, respectively). Each participant reported one partner who needed to be notified. The participants' median age was approximately 30 years old and they had been diagnosed with PID (N = 85), hepatitis B (N = 49), trichomoniasis (N = 45), syphilis (N = 30), and gonorrhea (N = 16). Characteristics were comparable between groups. There was no statistical difference in the PN rates (95.6% vs. 90.2%, p = 0.116), while the PET rate was significantly higher in the nurse-led group (49.6% vs. 67.9%; OR 0.47, 95% CI: 0.27–0.81; p = 0.005). Having endured symptoms for <7 days, being pregnant and detection of STIs during antenatal/pre-operative blood tests were positive predictors of PET (OR: 3.34, 95% CI: 1.81–6.14; 18.70, 95% CI: 5.61–62.31; and 22.07, 95% CI: 6.46–75.41, respectively). In conclusion, video-based education is as effective as nurse-led education in terms of PN rate but results in lower PET.