A method and system are provided for requesting a disposition notification from each group member for an Instant Messaging (IM) message. A sender requests desired group members for a disposition notification for an IM message in a group messaging service. The sender on the transmission side constructs an IM message to include information on the group members designated by the sender and transmits the constructed IM message to an IM server. After receiving the IM message from the sender, the IM server generates IM messages corresponding to the group members based on the information included in the received IM message, and then transmits the generated IM messages to respective group members. Accordingly, only the group members that have received the IM messages can generate their own reports, and then transmit the generated reports to the sender, allowing the sender to receive the disposition notification only from desired group members.