Phenotype switch of vascular smooth muscle cells (VSMCs) plays an important role in the development of atherosclerosis (AS). Endothelial cells can regulate VSMC phenotypic switch by secreting exosomes, crucial mediators of intracellular communication. This study aimed to determine whether exosomal LINC01005 from oxidized low-density lipoprotein (ox-LDL)-treated human umbilical vein endothelial cells (HUVECs) plays a role in regulating VSMC phenotypic switch and to validate the underlying molecular mechanism. Exosomes were extracted from ox-LDL-treated HUVECs (ox-LDL-Exo) and then administered into VSMCs. VSMC phenotypic switch was assessed by determining VSMC phenotypic markers using western blot. VSMC cell proliferation and migration were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and wound healing assay, respectively. The interaction between miR-128-3p and LINC01005 or Krüppel-like factor 4 (KLF4) was analyzed by luciferase reporter assay. ox-LDL-Exo contained high expression of LINC01005. Inhibition of LINC01005 expression in ox-LDL-Exo abrogated the ox-LDL-Exo-induced VSMC phenotypic switch, proliferation, and migration. Furthermore, LINC01005 acted as a sponge of miR-128-3p to upregulate KLF4 expression. Moreover, miR-128-3p overexpression and KLF4 silencing in VSMCs attenuated the ox-LDL-Exo-induced VSMC phenotypic switch, proliferation, and migration. Collectively, exosomal LINC01005 from ox-LDL-treated HUVECs promotes VSMC phenotype switch, proliferation, and migration by regulating the miR-128-3p/KLF4 axis.© 2020 International Union of Biochemistry and Molecular Biology.