Fully monolithic infrared CCD arrays have been fabricated in InSb, and detection and readout with the arrays have been demonstrated. The device reported is a 20-element linear array combining MOS detectors and a four-phase, overlapping-gate surface-channel CCD. The CCD's are p channel and utilize implanted planar p-n junctions for fat-zero (FZ) input and charge output. The charge transfer efficiency of the present devices is 0.995, limited by lateral surface potential variations rather than surface states, the density of which is very low. The transfer gate timing can be changed to either multiplex the twenty detector outputs or add them to achieve time-delay-and-integration; operation in both modes will be shown. The detectivity of the array has been measured in the multiplexing mode for a 5-ms integration time, operating temperature of 65 K, and background flux of 1012photons . s-1. cm-2. These measurements yielded single-element peak D-stars above 8 × 1011cm. Hz1/2. W-1with an array average of 6.4 × 1011cm. Hz1/2. W-1.