A statistical analysis of the narrow-band Jovian kilometric radiation, or nKOM, observed by the planetary radio astronomy experiment (Voyager 1 and Voyager 2) from January to December 1979, is reported. Occurrence, polarization, and rotation period are studied. The sense of circular polarization changes with magnetic latitude of the observer. Left-hand polarized emission is associated with the northern hemisphere, which suggests a radiation mechanism in the ordinary mode. The emission is beamed in magnetic latitude with an obscuration at the equator, and the measured axial ratio increases with the magnetic latitude of the observer. The nKOM source regions do not rotate with a single period and coherent phase. Long-term variations in the rotation are shown, the dominant regimes being system III and 2.5-3% corotation lags. During sequences of corotation with system III, the nKOM events are observed mainly in the ranges 40¿ and 300¿ central meridian longitude.