In the present study, the function of microRNA (miR)‑140‑5p on oxidative stress in mice with atherosclerosis was investigated. A reverse transcription‑quantitative polymerase chain reaction assay was used to determine the expression of miR‑140‑5p. Oxidative stress kits and reactive oxygen species (ROS) kits were used to analyze alterations in oxidative stress and ROS levels. The alterations in protein expression were determined using western blot analysis and an immunofluorescence assay. miR‑140‑5p expression was increased in mice with atherosclerosis with hypertension. Consistently, miR‑140‑5p expression was also increased in mice with atherosclerosis. Upregulation of miR‑140‑5p increased oxidative stress and ROS levels by suppressing the protein expression of nuclear factor erythroid 2‑related factor 2 (Nrf2), sirtuin 2 (Sirt2), Kelch‑like enoyl‑CoA hydratase‑associated protein 1 (Keap1) and heme oxygenase 1 (HO‑1) in vitro. By contrast, downregulation of miR‑140‑5p decreased oxidative stress and ROS levels by activating the protein expression of Nrf2, Sirt2, Keap1 and HO‑1 in vitro. Sirt2 agonist or Nrf2 agonist inhibited the effects of miR‑140‑5p on oxidative stress in vitro. Collectively, these results suggested that miR‑140‑5p aggravated hypertension and oxidative stress of mice with atherosclerosis by targeting Nrf2 and Sirt2.