In a continued effort to ensure high-quality data from the increasingly multi-lingual and multi-ethnic universe of respondents, the ACS language team at the Census Bureau took the initiative to develop translations of ACS supporting documents into multiple languages including Spanish, Chinese, Korean, and Russian. The Cognitive Testing of Translations of ACS Supporting Materials in Multiple Languages, Project A, was designed to evaluate two versions of a multilingual brochure that are included in a Pre-Notice mailing packet and an initial questionnaire mailing. Through cognitive interviews, the Census Bureau, RTI International, and Research Support Services (RSS) will determine whether these materials meet the Census Bureau Pretesting Standard (U.S. Census Bureau, 2003) and the Census Bureau Guideline for Translation (U.S. Census Bureau, 2004). This research will also help the Census Bureau determine if the respondents who see the translated documents have a similar understanding of the intended communication as the English-speaking respondents, and will identify what types of messages are conceptually difficult to translate effectively and what can be done to overcome this difficulty. The languages tested for this task include Spanish, Chinese, Korean, and Russian, as well as English, for comparative purposes.