For this project, ACT developed math and science items that attempted to represent unique aspects of cultures, raise awareness of social justice issues, promote cultural learning, be authentic and relatable, be comprehensible, and represent people in positive, nonstereotypical ways. Creating culturally relevant items was a new challenge for ACT test developers, and it involved many rounds of review by diverse content experts. The developers learned that creating culturally relevant items is a more demanding process, but they all reported that it was a positive, enriching experience. During focus groups, high school students viewed the culturally relevant items alongside non--culturally relevant items measuring the same skills. The students expressed interest in seeing culturally relevant items on the ACT, and they reported learning about cultures from the items. However, many students expressed concern about the additional time required to answer longer items during a timed high-stakes assessment like the ACT.