In this study a new record of Ganoderma tropicum is described as from Chiang Rai Province, Thailand. The fruiting body was collected on the base of a living Dipterocarpus tree. The sample is described on the basis of morphological characteristics and phylogenetic analyses, and compared with closely related taxa. Multigene phylogenetic analyses of LSU, ITS, and RPB2 highly support the placement of the G. tropicum group with isolates from China and Taiwan (Maximum likelihood 100%, Maximum parsimony 100%, and Bayesian posterior probabilities 1.00). The optimal media, pH, and temperature for mycelial growth of the G. tropicum strain KUMCC18-0046 was also investigated and is reported as: PDA, MEA, and YPD, at pH 7–8 and 25–28 °C, respectively. This is the first report on the successful growing conditions for mycelial production, but unfortunately fruiting could not be achieved.