The purpose of this study was to examine the qualities of muffins with 20, 40, and 60% brown rice flour (BRF). The muffins containing 20, 40, and 60% BRF were lower than control muffins (made with regular flour) in weight, height, pH, and moisture content. No significant differences were observed between BRF muffins in weight and moisture content; however, height and pH decreased with increasing amounts of BRF added (p<0.05). The moisture content of control muffins decreased after storage at $30^{circ}C$ and was not significantly different than BRF muffins (p>0.05). The hardness and resilience in the controls were higher than BRF muffins, but increasing the amount of BRF added in muffins increased both hardness and resilience (p<0.05). The cohesiveness and springiness in the controls were higher than in BRF muffins and decreased with increasing the amount of BRF added to muffins (p<0.05). The gumminess and chewiness in muffins with BRF were higher than controls and were increased when the amount of BRF added in muffins was increased (p<0.05). However, the adhesiveness of the samples was not significantly different (p>0.05). In sensory evaluation, the external color in muffins with 20% BRF and the internal color in controls were the highest (p<0.05). The taste, aroma, texture, and overall acceptability were the highest in muffins with 60% BRF (p<0.05). The antioxidant activities, DPPH radical scavenging, and superoxide dismutase-like activity of muffins were increased with increasing the amount of BRF added to muffins (p<0.05).