Sitka spruce is the most important tree species in Irish forestry (ca 55% of current planting programme) and this situation is unlikely to change in the future, despite an increase in the planting of other species. It is the only species for which there is an advanced breeding programme and it has the greatest potential to improve yields. Sitka spruce grows better on a wider range of sites in Ireland than any other species. It is envisaged that rotation length could be reduced from current 40-45 years to 25-30 years through genetic improvement. Thinning yields from improved crops, from <15 years onward, would yield significant amounts of small material, suitable for pulping or other purposes (e.g. pellets for energy production). Improved trees also sequester carbon (thus helping to mitigate effect of excess CO2) at a faster rate than unimproved stock. The concept of using improved material on certain sites to compensate for the potential shortfall in yield on other sites (mostly broadleaves) is consistent with the principles of Sustainable Forest Management. New research work is needed to improve the delivery of improved Sitka spruce material into use and to improve the efficiency of the selection process.