Intra-articular injections of hyaluronic acid (HA) or platelet-rich plasma (PRP) have been used in the treatment of temporomandibular joint (TMJ) arthrocentesis to improve lubricative properties and influence regenerative processes. This study aimed to evaluate the potential clinical benefits of complementary bioviscosupplementation with hyaluronic acid (HA) and platelet-rich plasma (PRP) in patients undergoing double-portal TMJ arthrocentesis. A total of forty-six patients (33 females, 13 males; mean age of 45.83 ± 20.62 years) with arthrogenous temporomandibular disorders, identified through clinical and imaging examinations, were randomized into HA+PRP (23 patients) or HA-alone (23 patients) groups. The primary outcome variable was TMJ arthralgia; the secondary outcome was maximum mouth opening (MMO). All the outcome variables were assessed preoperatively (T0) and at several follow-ups (T1-1 month, T2-3 months, T3-6 months, T4-12 months follow-up). The HA+PRP group presents lower TMJ arthralgia levels than the HA group at every follow-up moment ( < 0.05, r ≈ 0.3). At T3 and T4, the HA+PRP group presented a higher MMO average than the HA group ( = 0.03 and = 0.02; r ≈ 0.3). At T4, the HA group's success rate was lower than the HA+PRP group (65% vs. 96%), and a higher number of postoperative reinterventions were observed (35% vs. 4%). In this study, complementary intra-articular bioviscosupplementation (HA+PRP) following double-portal TMJ arthrocentesis was associated with better clinical outcomes regarding TMJ arthralgia reduction, MMO improvement, and reduced risk of future TMJ reintervention.