In ZigBee cluster-tree network, the existing literature works did not provide combined solution for co-channel interference and power efficient scheduling. In addition, the technique that prevents network collision is not explained. In order to overcome these issues, in this paper, we propose Energy Efficient Cluster Scheduling and Interference Mitigation for IEEE 802.15.4 Network where a time division cluster scheduling technique is considered that offers energy efficiency in the cluster-tree network. In addition, an interference mitigation technique is demonstrated which detects and mitigates the channel interference based on packet-error detection and repeated channel-handoff command transmission. By simulation results, we show that the proposed technique reduces the energy consumption and the network collision, thus enhancing the performance.