This study revisited the effectiveness of idle land taxation (ILT) as a land use regulatory policy. The uniqueness of ILT as a hybrid policy, which embodies both real property taxation and land use regulation features, was highlighted. The gaps between land use planning and real property taxation sectors were identified, and used to understand ILT’s viability as a land use regulatory policy. An in-depth case study was conducted in Tagaytay City given its long institutional experience in ILT implementation since 2002. Findings showed that for ILT to lessen the extent of idle land proliferation, factors such as consistent political support, strong organizational capacity, established land development framework, and rational real property valuation and taxation must be present. This study also highlighted that the imposition of idle land taxes is not necessarily punitive given low land values due to low market demand. In sum, it was observed that ILT could be used as a catalyst of land development, but is most effective when the institutional instruments and land market forces are working together.