This study presents the purification and detailed biochemical characterization of serine protease inhibitors (PIs) from chickpea (Cicer arietinum L.) seeds, with specific activity against trypsin and chymotrypsin. A sequential purification protocol involving ammonium sulfate fractionation, ion exchange chromatography (CM-Cellulose), and gel-filtration (Sephadex G-75) was employed. The inhibitory activity was quantified using synthetic chromogenic substrates (BAPNA for trypsin; BTEE/SAAPFpNA for chymotrypsin). Two major inhibitor fractions (CPI-I and CPI-II) were isolated. CPI-I (≈20 kDa) exhibited dual specificity, inhibiting both trypsin and chymotrypsin, characteristic of the Bowman-Birk inhibitor (BBI) family. CPI-II (≈8 kDa) showed strong specificity for chymotrypsin. Biochemical characterization included determination of kinetic parameters (Ki, IC₅₀), pH and thermal stability profiles, and susceptibility to reducing agents. The inhibitors were stable over a broad pH range (4-10) and retained significant activity after incubation at 70°C for 15 minutes. These findings highlight chickpea as a rich source of stable, bi-functional protease inhibitors with potential applications in nutrition, therapeutics, and plant protection.