This study aims to develop plant-based burgers with partial replacement of texturized soy protein (TSP) by Agaricus bisporus mushrooms at proportions of 5%, 10%, 15%, and 20%. The substitution was evaluated regarding its impact on the burgers’ chemical composition, texture, color, cooking performance, and sensory properties. Chemical analyses showed a significant increase in moisture content starting from the 10% substitution level, contributing to improved juiciness. Protein content remained similar to the control until the 15% substitution level, while the fat content showed no significant variation among treatments. The texture profile indicated reduced hardness in burgers with mushroom enrichment, particularly at 5% and 10%, leading to a more tender product. Color analysis revealed a reduction in lightness (L*) and red intensity (a*) with increased mushroom levels. Sensory analysis showed that burgers with up to a 15% substitution level maintained consumer acceptance comparable to the control, with attributes such as “softness”, “pleasant color”, and “good appearance” positively correlated with consumer acceptance. The findings indicate that Agaricus bisporus mushrooms can be effectively used as a partial substitute for TSP in plant-based burgers, enhancing sensory properties without compromising quality. This substitution offers a promising approach to diversifying ingredients in plant-based products while maintaining desirable characteristics for consumers.