Poly(N-vinylcaprolactam) (PNVCL) is a temperature-responsive polymer, only second to poly(N-isopropylacrylamide), the most popular temperature-responsive polymer. Its applications include its use in cosmetics, as an anticlogging agent in pipelines and increasingly, in biomedical applications. This review highlights the controlled synthesis of PNVCL in different architectures: random copolymers, block copolymers, graft copolymers, nanogels, and their applications in the biomedical field, e.g., drug delivery, cell detachment, entrapment of enzymes, tissue engineering, among others. Emerging applications in areas that are expected to grow are also presented where PNVCL will play a pivotal roll: nanotechnology and the environment.