Taboo English is an area of inquiry that has been overlooked in the research literature. Little appears to be published on the phenomenon of taboo language and its teaching implications for adult ESL/EFL students learning conversational English. This study aimed to investigate the attitudes and opinions of 80 ESOL teachers from 10 language schools in Auckland, New Zealand, towards the use of Taboo English in society and their attitudes towards teaching about taboo language to adult learners of conversational English. The project used a questionnaire designed to elicit a combination of both qualitative and quantitative data. Results showed that Taboo English was a valuable aspect of ESOL teachers' linguistic repertoire and that both males and females used taboo words in complex and diverse ways to communicate ideas quickly and efficiently. One of the key findings of the study contradicted the typical stereotype that females are more conservative in their taboo use than males. Another major theme that emerged was the linguistic prejudice towards teaching about Taboo English in the second language classroom. The vast majority of ESOL teachers in the study displayed little, if any, enthusiasm for teaching about taboo words to adult learners of conversational English despite acknowledging that taboo words are frequently heard in society today. This study concludes that Taboo language is an undeniable reality of English language use and that ESOL teachers, preparing adult learners to understand everyday language they will be exposed to in the 'real' world, need to address Taboo English to some degree. By not addressing this controversial language, teachers are insufficiently preparing learners to become empowered communicators in English.