Teak harvest in Northern Thailand in 1985 was only one-tenth that in 1971. The dramatic decrease has been attributed by some authors to loss of trees through shifting cultivation and intensification of modern agriculture. This study examined the possibility that previous removal of large trees during selective logging is also a reason for present low yields of teak. In a selectively logged mixed deciduous forest, most of the remaining teak was concentrated in diameter size classes less than 50 cm. In contrast, most of the teak stumps were larger than this diameter. The large trees had been removed by logging. Reduction of teak production in Thailand to the point where sustainable, profitable yield is no longer possible may have resulted from over-intensive harvest of large trees.