We investigated wound healing in trees after a thinning operation by a cable logging system with a short-span tower yarder. An observation plot was arranged in a plantation of Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa) located near to Kami City, Kochi Prefecture, Japan. A total of 137 wounds were recorded on 53 damaged trees among a total of 132 surveyed trees, both immediately after thinning and nine years later. Wounds were scored on the basis of their appearance using a scale with five degrees of severity. The width and length of wound areas were recorded, excluding any healed wounds in the resurvey. In addition, sixteen of the target trees were selected and felled, and the internal discoloration due to damage was investigated. Comparing the damage situation after nine years to that at the time of occurrence, there was no damage that worsened in degree of severity, and there was a trend toward recovery, but the areal extent of damage was greater in some cases than immediately after the operation. The internal discoloration was equal to or greater than the initial recorded damage, regardless of the extent of the damage. The discoloration width was approximately twice as large as the original damage width, and the discoloration length was approximately three times as large. This indicates that it is important to minimize damage during thinning and collection operations to reduce internal discoloration.