An important part of cognitive status evaluation is the determination of general cognitive ability. However, the most common tests are not standardized for use in Ecuador. This has limited the extent and accuracy of clinical neuropsychological assessments within the country. We used the 7-subtest Wechsler Adult Intelligence Scale-IV (WAIS-IV) with 155 mainly city-living Ecuadorian adults, recruited from a range of socioeconomic backgrounds around 4 different sites in Ecuador. The sample was matched to the Ecuadorian urban population for gender, education, and ethnicity. We show that this version of the WAIS-IV is a reliable and valid assessment for this context. In addition, we provide a method to adjust standard scores derived from the Spanish population, and used in the WAIS-IV manual, so that they are more appropriate for use in Ecuador. These can potentially be used to calculate full IQ scores. We also describe methods of comparing the Ecuador-adjusted standard scores so that they can be used in clinical neuropsychological evaluations of Ecuadorian adults.