In 1987, some 1.8 million tree deaths resulted from a Sirex noctilio outbreak in Pinus radiat'a plantations in southeastern South Australia and southwestern Victoria. The effects of the subsequent measures to deal with the outbreak are evaluated. The major response was to inoculate 147 000 trees with the parasitic nematode Deladenus siricidicola. Projects to salvage S. noctilio-infested trees and to release the parasitoid Megarhyssa norioni were also implemented. The inoculation programme cost $A 1.3 million. Productivity and costs were calculated for the seven procedures used to introduce the nematode: efficiencv was increased by using machine to fell and trim the trees and by redesigning the inocuiltion hammer. In addition, 2247 individuals of the parasitoid Megarhyssa nortoni were released At 35 sites in compartments with >5% tree mortality. Finally, salvage logging operations were carried out over a total of 1483 ha of thinned compartments. Some sanitation fellings were also made. Some 38 000 m' of sawlogs and 12 500 m 3of pulpwood were produced. Salvaged sawlogs were of low quality, with highly variable moisture content, and yielded sawn timber with various defects. Salvaged pulpwood had high resin content (2.2% on dry wood, compared with the normal content of 1.8%), leading to less efficient pulping. Knowledge, gained from this outbreak should prompt a review of the control recommendations. Forest managers should implement a rigorous control programme as soon as S. noctilio is detected in a region, to minimize the risk of a future outbreak. none