The surface of camera‐based medical devices is easily smeared by blood and fog during the surgical procedure, causing visual field loss and bringing great distress to both doctors and patients. In this article, a slippery liquid‐infused porous surface (SLIPS) on a quartz window surface that can repel various liquids, especially blood droplets is reported. A femtosecond laser pulse train was used to create periodic microhole structures on the silica surface. The subsequent low surface energy treatment and lubricant infusion led to the successful preparation of a slippery surface. Such blood‐repellent windows exhibited high transparency, great antifogging, and antibacterial properties. In addition, the slippery ability of the as‐prepared surface exhibited outstanding stability since the surface could withstand harsh treatments/environments, such as repeated pipette scratches and immersion in different pH solutions. The as‐prepared millimeter‐sized quartz samples with SLIPS were attached to the endoscope lens as a protective coating and could maintain high visibility after repeated immersion in blood. We believe that the coating developed in this study will provide inspiration for the design of next‐generation endoscopes or other camera‐guided devices that will resist fouling, keep clear vision, and reduce operation time, thus offering great potential applications in lesion diagnosis and therapy.