The 2009 Sumatra, Indonesia earthquake attacked Padang, which is the capital of West Sumatra province, and damaged a large number of reinforced concrete (R/C) buildings. The first author of this paper had conducted a post-earthquake field investigation in Padang. As a result, it was found that one of typical damage to buildings was beam-column joint failure. This damage was caused by poor structural details at joints, nevertheless appropriate details were provided in the Indonesian design regulation. In this study, the structural performance of a typical beam-column joint was experimentally evaluated to investigate the seismic performance of earthquake-damaged buildings. The test results revealed that joint failure occurred prior to beam/column yielding. This means that the actual seismic performance of damaged buildings was less than the design calculations in which joint failure had not been assumed.