205 patients (299 knees) with symptomatic osteoarthritis were included in this randomized controlled trial to determine if the addition of intraarticular corticosteroid infiltration to joint lavage provided additional benefits in terms of pain and clinical outcomes. Patients were randomized in a 4:1 ratio to receive joint lavage with intraarticular corticosteroid infiltration or joint lavage alone. The results at 3 months demonstrated no between-group differences for pain and clinical outcomes, with the exception of restricted motion and crepitation, which were significantly greater in the corticosteroid group.