The purpose of this study is to investigate the complex relationship between key profitability indicators and the performance of Indias top five nationalised banks according to Nifty PSU Bank Index are - State Bank of India (SBI), Bank of Baroda (BOB), Canara Bank (CB), Punjab National Bank (PNB), and Union Bank of India (UBI). The study is based on secondary data obtained from the Money Control Database of the respective banks. The study covers time duration of five years i.e., from 2018–19 to 2022–2023. Profitability ratios like Return on Equity (RoE), Return on Assets (RoA), Net Interest Margin (NIM), and Net Profit Margin (NPM) are utilized, along with statistical techniques, for analysis. The findings of the study reveal that the State Bank of India (SBI) stands out as a symbol of strength and stability with impressive returns. Union Bank of India (UBI) is still facing difficulties, therefore strengthening its deficiencies, and reducing performance variability would require concentrated effort. As Punjab National Bank (PNB) experiences financial downturns, it is imperative that corrective action be taken quickly. In this context, Bank of Baroda (BOB) exhibits a noteworthy Net Interest Margin (NIM), but Canara Bank (CB) encounters difficulties in this regard.