Polycaprolactone (PCL) is a biodegradable polymer widely used for medical implants and devices due to its biocompatibility, processability, and tunable degradation behavior. This study explores the incorporation of a thiazole-based antimicrobial compound into PCL at varying concentrations to develop new composite materials with both biodegradability and antibacterial function. Samples were solution cast and characterized using techniques like X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV–vis spectroscopy, antibacterial assays, and computational density functional theory (DFT) modeling. XRD showed up to 54 % crystallinity at the highest 0.03 g dye loading, indicating the thiazole impacted ordering and lamellar packing. FTIR and DFT calculations demonstrated multiple possible intermolecular bonding modes between the compounds. UV–vis spectra revealed the superimposed absorptions of the PCL matrix and emergent thiazole chromophore. Antibacterial tests exhibited marked growth inhibition of both gram-positive and gram-negative bacteria proportional to the thiazole concentration. The customizable PCL-thiazole blends offer biocompatible materials with functional antibacterial behavior for specialized applications in biomedicine.