Water is an essential resource for the survival of all living things and plays a critical role in human health, the continuity of ecosystems, and economic activities. However, anthropogenic activities arising from developing industries and a growing population are negatively impacting this indispensable resource. Dyestuffs released as a result of developing industries are carried into soil, air, and water resources, causing environmental pollution. Among these dyes, reactive red 141 (RR141), due to its high solubility, reactivity, and toxicity, poses a significant environmental threat and serious risks to human health and ecosystems. Therefore, it must be treated with appropriate methods. Biosorption is the preferred method for treatment. Eggshells, considered worthless and discarded as waste, were used as biosorbents. In recent years, waste considered garbage in water pollution studies has been incorporated into the biosorption process. Accordingly, in this study, the removal potential of membrane-separated blue eggshell powder (BESP) in its native form without any modification was investigated as an environmentally friendly, economical, and effective biosorbent material. A batch biosorption process was used in the study. The effects of BESP amount (0.1-1 g), contact time (5-90 min), pH (2-10), and temperature (20-35 0C) on the removal efficiency were evaluated. Under optimum operating conditions (pH: 4; time: 30 min.; BESP dose: 0.5 g; temperature: 20 0C), the maximum RR141 removal efficiency was found to be around 81%.