The aim of this study was to evaluate the effect of a single per operative injection of sodium hyaluronate (HA, Viscoseal¯) into the knee following arthroscopy. This was a prospective, randomised controlled study. Knee arthroscopy patients were randomised into two groups: one receiving bupivicaine and the other sodium hyaluronate. Pre and post operative VAS scores for pain and Western Ontario and MacMaster Universities (WOMAC) scores for knee function were obtained. Forty eight patients of a single surgeon were randomised into two groups of 24. Both groups were similar as regards to age, sex, etc. Three patients withdrew from the study after randomisation. There was significant drop in pain scores for the Viscoseal¯ group compared to Bupivicaine group particularly between three-six weeks period (p< 0.05) and a significant improvement in WOMAC scores in the study group compared to control at 3 and 6 weeks (p=0.01). Viscosupplementation after arthroscopic knee surgery offers significantly improved function and pain relief over the medium term period (three-six weeks).