Alien conifers have been widely planted in the Southern Hemisphere. Australia, New Zealand and South Africa, all with long histories of alien conifer planting, have major problems with invasive conifers (“wildings”). Widespread planting of alien conifers has a much shorter history in South America, and invasions are a recent phenomenon. A workshop was convened in Argentina in May 2007 to discuss the rapid emergence of problems with invasive conifers in South America. Workshop delegates agreed that: the problem is likely to increase substantially and rapidly in many parts of the continent; the problem is not widely recognized; lessons from elsewhere can be transferred; and collaboration can bring benefits. The need was expressed: for an accurate assessment of the dimensions of the problem; to raise awareness of the problem; for a common research agenda; to initiate management interventions. This paper summarizes the key aims, deliberations, and planned outcomes of the workshop.