Background Patients with wake-up ischemic stroke who have evidence of salvageable tissue on advanced imaging can benefit from intravenous thrombolysis. It is not known whether patients who do not fulfil such imaging criteria might benefit from treatment, but studies indicate that treatment based on non-contrast CT criteria may be safe. Tenecteplase has shown promising results in patients with acute ischemic stroke. The aim of the Tenecteplase in Wake-up Ischemic Stroke Trial (TWIST) is to compare the effect of thrombolytic treatment with tenecteplase and standard care versus standard care alone in patients with wake-up ischemic stroke selected by non-contrast CT. Methods/design TWIST is an international, investigator-initiated, multi-centre, prospective, randomized-controlled, open-label, blinded end-point trial of tenecteplase ( n = 300) versus standard care ( n = 300) in patients who wake up with an acute ischemic stroke and can be treated within 4.5 h upon awakening. Seventy-seven centres in 10 countries (Denmark, Estonia, Finland, Latvia, Lithuania, New Zealand, Norway, Sweden, Switzerland, and the United Kingdom) participate. The primary outcome is the modified Rankin Scale on the ordinal scale (0–6) at three months. Discussion TWIST aims to determine the effect and safety of thrombolytic treatment with tenecteplase in patients with wake-up ischemic stroke selected by non-contrast CT. Trial registration ClinicalTrials.gov NCT03181360. EudraCT Number 2014-000096-80.