OBJECTIVE: The use of continuous paravertebral (PV) catheters for management of acute postsurgical pain after video-assisted thoracoscopic surgery (VATS) has not been investigated previously as a randomized controlled trial. The purpose of this study was to compare the efficacy of an ultrasound-guided continuous PV catheter catheter infusion for postoperative pain control with single-shot intercostal blocks (ICB). DESIGN: A prospective, randomized, controlled trial. SETTING: An academic university hospital. PARTICIPANTS: Patients (>/=18 years of age) who underwent a VATS procedure. INTERVENTIONS: Patients were randomized into 2 groups. Group 1 received single-shot ICB. Group 2 received an ultrasound-guided PV catheter with a continuous infusion of 0.2% ropivacaine. MEASUREMENTS AND MAIN RESULTS: There were 25 patients in group 1 and 23 patients in group 2. The maximum pain score was significantly lower in the group that received the PV catheter compared with those who received ICB during 24 to 48 hours (3.65 v 6.44, p<0.001). Seventeen patients (74%) who received PV catheters reported satisfaction with a pain control regimen compared to the 11 (44%) who received ICB (p = 0.036). In addition, during 24 to 48 hours after surgery the mean opioid use decreased significantly in the PV catheter group (14.39 v 30.50 mg morphine equivalents, p = 0.046). CONCLUSIONS: Ultrasound-guided continuous PV catheter infusions provided prolonged pain control and superior patient satisfaction compared with single-shot ICB after video-assisted thoracoscopic surgery.