Autoclaved aerated concrete (AAC) is an attractive building material with lightweight, good insulation, fireproofing, and durability characteristics. The seismic response of AAC requires an in-depth understanding as its use as infill walls is gaining popularity in seismically active regions of many countries in Europe, Middle East, and Asia. Recent studies on the seismic response of AAC infill walls were mostly conducted on solid AAC walls without considering openings and simulated earthquake loading was applied in the plane of the frame. In this study, recent tests on the out-of-plane and in-plane seismic response of AAC infill walls with openings were investigated experimentally. The door opening was considered for the purposes of the study. The limited deformation capacity of the AAC infill walls was observed. An innovative system to improve the performance of AAC infill walls was briefly discussed.