Abstract This study aims to describe the production of English monophthongs by nonnative Saudi speakers. It acoustically examined the production of English monophthongal vowels by Saudi second language (L2) speakers. Sixteen L2 participants produced twelve English monophthongs in carrier words. Comparable data were obtained in native Saudi Arabic and native Southern Standard British English to aid interpreting the L2 results. Formant frequencies and durations were measured for all vowels. Similar to Saudi Arabic, the English vowels produced by the Saudi L2 speakers occupied a smaller vowel space than the vowels produced by the native English speakers. There was overlap between many of the English vowel categories produced by the L2 speakers. However, the L2 speakers were found to employ similar durational characteristics to those employed by the native English speakers. L1 influence seems to play a major role in the L2 learners’ production of English vowels. The limited vowel space of the L2 speakers’ L1 appears to have limited their ability to produce the more acoustically peripheral English vowels.