The present research combines two important factors, cultural influence on SLA and wait-time. The research investigates how multi-ethnic students react differently to extended wait-time as an instructional strategy in the ESL classroom. Some research has been conducted on production as influenced by manipulated wait-time. However, no research has attempted to investigate the comparison of production after manipulated wait-time by ethnicity of students in the ESL classroom. It was hypothesized that when given extended wait-time, all students would increase students’ oral production. Especially, Asian students would increase the number of words to a higher degree than Non-Asians do. A multi-ethnic ESL classes were observed for quantitative findings, and their students and teachers were interviewed for qualitative one. It was found that oral production increased when the wait-time was increased. Unexpectedly, however, non-Asians produced more words to a higher degree than Asians did, as wait-time increased. It was interesting to find from the interview that there was a difference in students’ attitude towards wait-time. Some thought wait-time could cause more anxiety rather than comfort. This research will be significant in that the result could contribute to the improvement of teaching English in multi-ethnic classrooms.