Quinoa is a good gluten-free option for making bread, but it lacks the properties that make bread soft and fluffy. By adding soy protein isolate (SPI) to quinoa dough, the physical properties improved significantly. The dough became more similar to wheat dough, needing more water but having better texture. When 8% SPI was added, the bread quality and texture improved, coming closer to wheat bread. This study shows that using SPI can help make higher-quality gluten-free bread.