OBJECTIVE In an attempt to improve the recovery and early rehabilitation after arthroscopic knee surgery, various medications have been administered via intra-articular route to prolong the duration and improve the quality of postoperative analgesia. Among the potentially effective substances, steroids like dexamethasone could be of particular interest. METHODS Fifty patients undergoing elective knee arthroscopy were randomly assigned to one of the following groups containing 25 patients each. Group D patients received 8 mg (2 mL) of dexamethasone added to 18 mL of 0.25% levobupivacaine intra-articularly, (total volume 20 mL). Group L patients received 18 mL of 0.25% levobupivacaine and 2 mL of isotonic saline (20 mL in total) intra-articularly. Analgesic effect was evaluated by measuring pain intensity visual analogue scale score and duration of analgesia. RESULTS A longer delay was observed between intra-articular injection of study medication and first requirement of supplementary analgesic in Group D (10.24 ± 2.8 hours) compared with Group L (5.48 ± 1.6 h). Total consumption of diclofenac sodium in first 24 h in postoperative period was significantly less in Group D. No significant side effects were noted. CONCLUSIONS Dexamethasone, used as adjunct to levobupivacaine in patients undergoing arthroscopic knee surgery, improves the quality and prolongs the duration of postoperative analgesia.