We report on novel physical effects in symmetric planar chirowaveguides. First, these symmetrical chiral structures can support leaky waves while their achiral counterparts cannot. Second, leaky waves from these structures primarily exhibit polarization with a handedness opposite to that of the guided waves. These leakage effects may be used to design novel devices in microwave, millimeter wave and optical wave integrated circuits, such as directional couplers, mode strippers, polarization converters and leaky-wave antennas.