The Wada Memorial Award was created in 2011 to encourage the submission of high-quality papers to Cytologia. Coincidentally, the first to fourth holders of the award were experts in karyotype and chromosome analyses among the three regions of the Indomalayan biogeographic realm. Most of Indomalaya was originally covered by tropical and subtropical moist broadleaf forests, with high biodiversity that is currently at risk due to various anthropogenic influences. Karyotype and chromosome analyses provide an essential foundation for maintaining biodiversity through conservation; therefore, in this paper, we focus recent their contributions of the early Wada Memorial Award winners to the three regions of Indomalayan