Chimeric antigen receptor (CAR)-engineered natural killer (NK) cells have emerged as a promising new frontier in cancer immunotherapy. Building on the successes of CAR-T cell therapies, CAR-NK cells offer several potential advantages that make them an attractive option for treating various malignancies. NK cells can recognize and eliminate malignant or infected cells using an array of invariant activating and inhibitory receptors, without prior sensitization or antigen presentation. This inherent ability combined with genetic engineering to express CARs allows CAR-NK cells to target specific tumor antigens while retaining their natural cytotoxic mechanisms. Additionally, CAR-NK cells have an excellent safety profile, even when being transferred from healthy donors to patients without HLA matching. Recent advances in CAR design, NK cell sourcing, and genetic modification techniques have accelerated the development of CAR-NK cell therapies. However, difficulties in the cultivation, genetic modification, functional testing, and upscaling of NK cells present a major challenge and limit the development of innovative NK cell-based gene therapy approaches. This chapter will guide through optimized processes for research and large-scale CAR-NK cell manufacturing including NK cell isolation, genetic engineering, CAR-NK cell expansion, and quality controls. Thereby, we aim to accelerate the development of novel CAR-NK cells to expand the reach and effectiveness of cellular immunotherapies against cancer.