Given the rich biological diversity in California and dramatic loss and modification of its habitats, populations, species, and ecosystems, a concerted effort has emerged to restore large areas of the state's public and private lands. Under these circumstances, ecological restoration represents an important element in the strategy to conserve numerous at-risk species and maintain vital ecosystem services. After reviewing the various motivations for ecological restoration, we identify some of the key challenges, both practical and theoretical, that are likely to affect the success of restoration efforts. We describe a shift in defining restoration success from a focus on recreating historic “pristine” ecosystems to viewing restoration in a dynamic landscape context in which realistic novel ecosystems are accommodated. These accommodations are necessitated by a broad array of challenges that include several global change factors. Finally, we argue that prospects for successful ecological restoration will be enhanced by emphasizing landscape-scale resilience and incorporating restoration into a regionally-coordinated, active adaptive management program.