With the lack of progress there has been so far on climate change, some have begun researching the potential of geoengineering to allay future climatic harms. However, others contend that such research should be abandoned. One of the most-cited reasons as to why research into geoengineering should be abandoned is the idea that such research sits at the top of slippery slope. The Slippery Slope Argument warns that even mere research into geoengineering will create institutional momentum, ultimately leading to the deployment of a technology that is untested and perhaps morally objectionable. This article clearly lays out the Slippery Slope Argument against geoengineering research and analyses its premises. I claim that both the empirical premise - that research will inevitably lead to deployment - and the normative premise - that we have decisive moral reasons to avoid deployment - are questionable. The main conclusion of the article is that while we should be cognizant of the potential for research to lead to undesirable deployment scenarios, engaging in research need not necessarily lead inexorably to deployment. While insufficient to ground a moratorium on research, the Slippery Slope Argument points to the need for regulation and oversight in order to prevent undesirable deployment.