A method and an apparatus for managing a broadcast for a portable terminal receiving supplementary information related to the broadcast are provided. The method includes tuning a broadcasting receiver of the portable terminal to a frequency from among a plurality of frequencies of a broadcasting channel, receiving, by the broadcasting receiver, a broadcasting signal on the tuned frequency, determining whether a moving speed of the portable terminal is equal to or more than a predetermined speed when a broadcasting receiver is tuned to the frequency and is receiving a broadcasting signal, measuring a field strength of the received broadcasting signal when the moving speed of the portable terminal is equal to or greater than the predetermined speed, and controlling the broadcasting receiver to be tuned to another frequency in order to receive the broadcasting signal of the broadcasting channel when the measured field strength is less than a predetermined threshold.