The short-term recovery period post-arthroscopic meniscectomy is characterized by pain and impaired function most likely related to the irrigation of synovial fluid from the knee intraoperatively. Consequently, along with removal of harmful debris, the irrigation fluid dilutes the hyaluronic acid layer covering the joint tissues. Hyaluronic acid contributes to the homeostasis of the joint environment and is an important component of synovial fluid and cartilage matrix. Hence, the instillation of hyaluronic acid after the procedure may relieve symptoms. This prospective, single-blind, randomized, controlled study evaluated clinical outcome after hyaluronic acid injection to patients who underwent arthroscopic meniscectomy of the knee. Patients with ligamentous injuries or severe chondral damage were excluded. Fifty-six patients with a mean age of 34 years (range, 17-44 years) were injected with Viscoseal (TRB Chemedica International S.A., Geneva, Switzerland) or normal saline immediately post-arthroscopy and divided into the Viscoseal group or control group, respectively. Patients were evaluated for pain, swelling, and function at 1, 4, and 12 weeks postoperatively. Patients in the control group reported more pain at week 1, with a mean visual analog score (VAS) of 43, than did patients in the Viscoseal group, with a mean VAS of 28 (P=.006). At 4 weeks postoperatively, none of the Viscoseal patients had consumed analgesics, where 9 (of 28) in the control group reported acetaminophen intake (P=.039). No significant difference in knee function was found between groups. Intra-articular injection of Viscoseal after arthroscopic meniscectomy reduced pain in the short-term recovery period.