In clinical settings, biofluid-contacting devices can suffer from biofouling, leading to thrombus formation and bacterial biofilm buildup, which impair device function and pose health risks. Traditional antifouling methods, including the use of hydrophilic polymers and heparin coatings, often suffer from instability and reduced bioactivity over time. Lubricant-infused surfaces (LIS) have emerged as a promising alternative due to their long-term stability and broad-spectrum repellency. However, current LIS technologies typically involve complex, multistep processes that restrict their application to surface layers, potentially compromising performance under mechanical stress. This study introduces a novel method for bulk modification of poly(vinyl alcohol) (PVA) films, creating flexible lubricant-infused PVA membranes with superior antifouling properties. These films are fabricated by cross-linking the PVA chains using n-propyltrichlorosilane (n-PTCS) and subsequent infusion with silicone oil as a lubricant. The modified PVA films significantly prevent bacterial adhesion and prolong blood and plasma clot formation. Additionally, these films exhibit enhanced mechanical properties, particularly in elasticity and flexibility compared to unmodified PVA films. The developed technique provides a straightforward method for creating flexible, super-repellent biointerfaces with the potential to prevent blood adhesion and bacterial biofilm formation, which are common complications associated with biofluid-contacting devices and medical implants.