A terahertz focal-plane array (FPA) for video-rate imaging applications has been fabricated in a commercially available CMOS process technology. The 3times5 pixel array uses conventional low-cost quarter-micron NMOS transistors for incoherent power detection. Each pixel has a size of 150times150 mum2 and consists of an on-chip antenna, an incoherent power detection circuit, and a 43-dB amplifier with a 1.6-MHz bandwidth. At 0.6 THz a pixel achieves a responsivity of 50 kV/W with a minimum NEP of 400 pW/radic(Hz). Images at 0.6 THz are presented which demonstrate the feasibility of the applied method and show the potential of silicon integrate terahertz FPAs for future low-cost terahertz camera systems.