In the mining industry, significant progress and increased mineral production cause waste disposal issues which is one of the crucial problems in mining operations. It leads to both environmental and economic issues. Particularly, wastes from the production of metallic sulfide ore cause serious environmental pollution. In the last three decades, waste has been stored in underground openings in a controlled manner as paste-fill. Paste-fill is created by waste, water, and chemical additives. In this paper, two types of wastes were chosen to investigate the usability of tailings as paste-fill material. A lead and zinc underground mine was selected as a research site located in Balikesir, Turkey. First of all, several tests were conducted to analyze the physical, chemical, and mineralogical characteristics of paste-fill materials. Then, one of the design of experiment methods was used to create different mixtures of paste-fill specimens by changing the binder ratio and water content as input variables for four curing times. Finally, the strength properties were obtained as output variables, and an optimum mixture of paste-fill was determined. The results show that the tailings can be used as paste-fill material to achieve environmental and economic benefits and provide a safe working environment.