Biological invasion is a major component of global environmental change and it has negative impacts on native biodiversity, ecosystem services, infrastructures, agriculture production, and human and animal health. Direct and indirect economic costs of biological invasions amount to several hundred billions of dollars annually. Lowlands with high urbanization, industrialization, and other economic activities are adversely affected by biological invasions, whereas mountain regions were considered to be relatively less affected by this phenomenon. However, recent research and meta-analyses have revealed that biological invasions are occurring in mountain regions at an alarming rate. Management of invasive alien species (IAS) is more challenging in mountains due to the rugged topography.