This study explores the weight of pronunciation in a speaking proficiency test at an English as a Second Language (ESL) Intensive English Program (IEP) in America. As an integral part of speaking, beliefs, practices, and research of pronunciation teaching have experienced shifts over the decades (Morley, 1991). Most studies concerning speaking have focused on intelligibility, comprehensibility, and accentedness of speaking, with attempting to address the role of pronunciation in oral communication. However, the degree to which pronunciation is weighed in determining speaking proficiency levels is unclear (Higgs & Clifford, 1982, Kang, 2013). In an effort to contribute to the understanding of this issue, the current study investigates the relationship between pronunciation and speaking proficiency ratings. The speaking proficiency ratings and pronunciation ratings in vowels, consonants, word stress, sentence stress, intonation, and rhythm of 226 speaking samples from English learners were collected at Brigham Young University's (BYU) English Language Center (ELC). The study confirms that suprasegmentals explain more variance than segmentals in English proficiency, and among those suprasegmental features, only the ratings of sentence stress increase incrementally with the proficiency levels without overlapping among proficiency levels.