FERIC studied four compact tracked harvesters and their associated forwarders working in commercial thinning. The harvesters produced wood at costs ranging from $7 to $33 per cubic metre, with forwarding costs adding $4 to $15 per cubic metre. The lowest costs were obtained with experienced operators using larger machines, but the smaller machines can also produce wood at an acceptable cost and may be more suitable in operations that produce insufficient wood annually to justify the costs of the more expensive machines. For optimal productivity, the harvester should be able to produce enough wood to keep the forwarder fully occupied.