Temporal lobe epilepsy is one of the most common types of epilepsy and is often drug-resistant. Furthermore, different types of cognitive deficits are very often seen in this type of epilepsy. Patients with drug-resistant epilepsy are typically directed to specialized epilepsy clinics for presurgical workup and possible resective surgery. When the noninvasive presurgical evaluation cannot reach a conclusion about lateralization of language and/or memory functioning, a more invasive technique such as the Wada or intracarotid amobarbital test should be considered. During this test, an anesthetic is locally injected in the carotid artery with the idea to temporarily “turn off” one cerebral hemisphere, while brain functions in the other hemisphere are preserved and can be tested to estimate its memory and language capacity, temporarily mimicking the situation after resective surgery. In this chapter, we discuss the benefits and side effects of the Wada test, its potential predictive value in the postsurgical language and memory performance, as well as specific scenarios when the use of the Wada test is indicated in addition to the noninvasive testing of language and memory (specifically with fMRI).