Background: Efficient approaches are needed for delivering nonpharmacological interventions for management of knee osteoarthritis (OA)., Objective: This trial compared group-based versus individual physical therapy interventions for management of knee OA., Design and Methods: Three hundred twenty patients with knee OA at the VA Medical Center in Durham, North Carolina, (mean age=60 years, 88% male, 58% nonwhite) were randomly assigned to receive either the group intervention (group physical therapy; six 1-hour sessions, typically 8 participants per group) or the individual intervention (individual physical therapy; two 1-hour sessions). Both programs included instruction in home exercise, joint protection techniques, and individual physical therapist evaluation. The primary outcome measure was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC; range=0-96, higher scores indicate worse symptoms), measured at baseline, 12 weeks, and 24 weeks. The secondary outcome measure was the Short Physical Performance Battery (SPPB; range=0-12, higher scores indicate better performance), measured at baseline and 12 weeks. Linear mixed models assessed the difference in WOMAC scores between arms., Results: At 12 weeks, WOMAC scores were 2.7 points lower in the group physical therapy arm compared with the individual physical therapy arm (95% confidence interval [CI]=-5.9, 0.5; P=.10), indicating no between-group difference. At 24 weeks, WOMAC scores were 1.3 points lower in the group physical therapy arm compared with the individual physical therapy arm (95% CI=-4.6, 2.0; P=.44), indicating no significant between-group difference. At 12 weeks, SPPB scores were 0.1 points lower in the group physical therapy arm compared with the individual physical therapy arm (95% CI=-0.5, 0.2; P=.53), indicating no difference between groups., Limitations: This study was conducted in one VA medical center. Outcome assessors were blinded, but participants and physical therapists were not blinded., Conclusions: Group physical therapy was not more effective than individual physical therapy for primary and secondary study outcomes. Either group physical therapy or individual physical therapy may be a reasonable delivery model for health care systems to consider., (© 2016 American Physical Therapy Association.)