Climate change creates new challenges for resource managers and decision-makers with broad and often complex effects that make it difficult to accurately predict and design management actions to minimize undesirable impacts. We review pertinent information regarding methods and approaches used to conduct climate change vulnerability assessments to reveal assumptions and appropriate application of results. Secondly, we provide managers with an updated summary of knowledge regarding vulnerability of species and habitats to climate change in the American Southwest. Overall, vulnerability assessments provided valuable information on climate change effects and possible management actions but were far from a comprehensive picture for the future of the Southwest. Scales, targets, and assessment approaches varied widely and focused on only a subset of resources. We recommend land managers critically examine methods when using assessment results; select scale, methods, and targets carefully when planning new assessments; and communicate assessment needs to researchers of climate change response.