Metal-insulator-metal (MIM) capacitor is an important passive component in RF, analog and mixed signal (RF-AMS) circuits. It takes a large circuit area of integrated circuits (ICs) compared to other passive and active components. So miniaturization of MIM capacitors, along with transistors, has become essential in design and fabrication of future ICs. This has made a trend to design high capacitance density MIM capacitors with novel dielectric materials. In this regard, many works were carried out in fabrication of various nanostructured high-k dielectricMIMcapacitors over the last decade. However, many of them suffered with structural defects, interface traps, and poor polarization process due to limitations of fabrication processes. The anodization process is an electrochemical oxidation of metalswhich had been demonstrated for the preparation of high-k dielectrics with improved crystalline properties, low structural defects, and improved ionic polarization. In this chapter, the fabrication and characterization of nanostructured anodic high-k MIM capacitors are presented. Many of these capacitors are meeting the requirements of International Technology Roadmap for Semiconductor with crystalline properties and improved ionic polarization. © The Institution of Engineering and Technology 2016.