Background: Mouthwashes have been used to improve gingiva health, owing to their anti-bacterial and fresh effects on the oral cavity. The interactions between mouthwash additives and these composites may impact the hardness, color stability, and overall functionality of restorative materials. Objective: The purpose of this study was to determine how three different commercially available mouthwashes affect the toughness and color stability of two different resin-based composite restorative materials, Bulkfil and Nanohybrid. Materials and Methods: The study involved testing two different a polymer-based resin dental composites (RBC): Bulkfill Restorative (3M/ Filtek, ESPE,A2, USA) and Nano Hybrid Universal Restorant (3M/1 Filtek 250 XT), which are available in the United States. The specimens were divided into three subgroups (n = 9) of each composite for testing with different mouthwash additives later. Each cycle consisted of complete immersion in a mouthwash for 21 minutes (equivalent to 3 weeks of use) followed by immersion in saliva for 12 hours at 37˚C. Results: The results showed that color stability (ΔE) of both composites affected significantly (p ˂ 0.05), while the micro hardness test didn’t show significant alteration after immersion cycle (p > 005). Conclusion: Within limitation of present study, it can be concluded that despite the color stability of the composites being affected by mouthwash, surface hardness remains substantially unaffected. The results of the current study may help dentists advise patients who have restorations on the best oral hygiene products to use, extending the life and durability of the dental work.