In this paper, a wide tuning-range CMOS voltage-controlled oscillator (VCO) with high output power using an active inductor circuit is presented. In this VCO design, the coarse frequency is achieved by tuning the integrated active inductor. The circuit has been simulated using a 0.18-mu m CMOS fabrication process and presents output frequency range from 100MHz to 2.5GHz, resulting in a tuning range of 96%. The phase noise is -85 dBc/Hz at a 1MHz frequency offset. The output power is from -3 dBm at 2.55GHz to +14 dBm at 167MHz. The active inductor power dissipation is 6.5mW and the total power consumption is 16.27mW when operating on a 1.8V supply voltage. By comparing this active inductor architecture VCO with general VCO topology, the result shows that this topology, which employs the proposed active inductor, produces a better performance.