A design methodology of CMOS LC voltage-controlled oscillator (VCO) is proposed in this paper. The relation between components and specifications of the LC-VCO is studied to easily identify its design trade-offs. This methodology has been applied to design ultra-low-power LC-VCOs for different frequency bands. An LC-VCO based on the current reuse technique has been realized with the proposed methodology in 0.13[Formula: see text][Formula: see text]m CMOS process. Measurements present an ultra-low power consumption of only 262[Formula: see text][Formula: see text]W drawn from 1[Formula: see text]V supply voltage. The measured frequency tuning range is about 10% between 2.179[Formula: see text]GHz and 2.409[Formula: see text]GHz. The post-layout simulation presents a phase noise (PN) of [Formula: see text][Formula: see text]dBc/Hz, while the measured PN is [Formula: see text][Formula: see text]dBc/Hz.