105 patients diagnosed with mild-to-moderate knee osteoarthritis were randomized to receive an intra-articular injection of botulinum toxin type A (BTA), triamcinolone hexacetonide (TH) or 0.9% saline. The primary outcome of interest was pain during movement, measured on a Visual Analog Scale (VAS). Secondary outcomes of interest included VAS pain at rest, the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index, the short form 36 (SF-36) quality of life questionnaire, the 6 minute walk test (6MWT), the timed up and go (TUG) test, range of motion (ROM) in flexion and extension, synovial hypertrophy and the incidence of adverse events. Follow up was performed at 4, 8 and 12 weeks post-injection. VAS pain during motion was significantly different among the three groups, with the TH group displaying the most favourable outcomes. There were no significant differences among the groups in all remaining outcomes.