Purpose: The fracture of acrylic resin dentures remains an unresolved problem. Over the years, various approaches to strengthening acrylic resin have been suggested, including modifying or reinforcing the resin. The aim of this study was to investigate the effect of chopped poly(methyl methacrylate) (PMMA) fibers on some properties of acrylic resin denture base material. Materials and Methods: PMMA in the form of fibers 0.75 mm in diameter and 5 mm in length was added to acrylic resin denture base material in various percentages to form a composite material. The influence on doughing and manipulation times and transverse strength was examined. The results were subjected to statistical analysis using a one-way analysis of variance and, where appropriate, the Scheffé test. Results: The results showed that the doughing time was decreased by the addition of fibers, with the manipulation and setting times showing inconsistent changes. There was a significant difference between the materials in terms of the transverse strength. When the amount of PMMA fibers in the acrylic resin was increased, there was a decrease in the modulus of rupture and a decrease in the modulus of elasticity. The differences were shown to be statistically significant in some groups. Conclusion: The doughing time was decreased by the addition of fibers, while the manipulation and setting times showed inconsistent changes. The incorporation of chopped, randomly oriented PMMA fibers into acrylic resin had no advantage over the unmodified polymer in terms of strength and cannot be recommended as a reinforcing agent for acrylic resin denture base material.