An apparatus and a method for providing a conference call service in a portable terminal are provided. The apparatus includes a communication unit for sending and receiving an IDentifier (ID) of a participant to take part in a conference call, schedule information of the participant, and conference call reservation information by communicating with a conference server, a display unit for outputting the ID, the schedule information, and the conference call reservation information, an input unit for generating input data for selecting the ID, and response data of a conference call connection request, a reservation information generator for identifying a participant to take part in the conference call by detecting the input data for the ID, sending participant information to the conference server, and generating the conference call reservation information including an available conference call schedule by receiving the participant schedule information from the conference server.