This paper proposes a new and effective communication protocol for the implementation of an automatic meter reading system using power-line communications (PLC) and presents analytical models to study its performance. The proposed protocol utilizes a novel packet routing system which combines “Request” and “Data” packets that enable meter units to send their metering data to the data concentrator and, at the same time, re-broadcast the “Request” to other meter units. It employs a carrier-sense multiple access with collision avoidance medium-access control protocol for the contention-based data transmission. The performance of the proposed protocol in terms of data-collection delay and throughput under impulsive noise interference is analyzed and compared with that of the neighbor relay polling (NRP) protocol. The proposed protocol does not require a central controller to initiate all data transmission unlike polling-based protocols and can be applied to PLC systems with unstructured networks. The proposed protocol ensures significantly lower data-collection delay than the NRP protocol. It will be able to achieve 100% throughput for light and moderate impulsive noise environments and 75% throughput for a heavy impulsive noise environment using broadband PLC with a cluster size larger than 60.