This paper explores a critical case study of the secant pile design of an underground railway station in Mumbai which is influenced by the construction of adjacent piles of elevated metro station. As construction is progressing for both projects, it is imperative to assess the mutual impact between the nearby elevated pile foundation and the secant pile of the underground station. This evaluation is crucial for design consideration and additional support system requirements. For secant pile wall design, geotechnical parameters are derived based on the geotechnical investigation carried out in the nearby area. Conversely, for the elevated metro station pile, all the necessary details for analysis, such as loading and pile cap contributory area, were furnished in the drawings by the elevated metro station designer. The Plaxis 2D software was utilized to analyze the overall stability of the system under various conditions. To cover all potential construction sequences, three cases were considered for analysis: Case 1—Elevated metro piles installation preceding underground station excavation, Case 2—Elevated metro pile installation following underground station excavation, and Case 3—simultaneously elevated metro pile and secant pile installation. The analyses reveal the necessity for an additional anchorage support system, particularly systematic rock bolts for global stability during rock slope excavation. By incorporating these findings, the paper provides results and insights from various scenarios and trials conducted to minimize the deflection in piles for both projects, ensuring the seamless construction of both underground and elevated structures without encountering issues.