An apparatus and method for receiving a packet data control channel in a mobile communication system that transmits packet data and has the packet data control channel for transmitting control information related to transmission of packet data are provided. A receiver receives and despreads a signal on the packet data channel and a signal on the packet data control channel, separately outputs the signals, and estimates a noise of a received signal. A signal level detector receives a noise estimation value and samples of the packet data control channel signal from the receiver, and outputs a validity signal for detecting whether information is received over the packet data control channel. A packet data control channel decoder decodes the packet data control channel signal if the validity signal received from the signal level detector is valid.