Fed-batch culture currently represents the typical choice for the production of monoclonal antibodies (mAbs) in the biopharmaceutical industry. However, the implementation of perfusion culture process combined with continuous manufacturing has gained attention due to increased productivity and resource savings. In this paper, we compared the host cell protein (HCP) production and profile of mAb1 between fed-batch and perfusion culture processes. Our work demonstrated differences in HCP production based on the type of cell culture process for the first time. We focused on HCPs that get carried through the purification process and are present in the final drug substance at levels impacting antibody quality and stability. Perfusion process had lower HCP levels and enabled higher clearance of problematic HCPs compared to fed-batch suggesting a viable alternative process. Furthermore, our work demonstrates proof of concept of the impact of cell culture process on specific product quality and help to navigate the process design when we move from traditional fed-batch to next-generation perfusion cell culture.