For more than 20 years, extensive reading(ER) has been reported to assist learners of English as a foreign/second language in developing their English proficiency and improving their attitude toward reading, vocabulary development, and reading motivation. Although previous studies have discussed the impact of ER on language learning in a wide range of areas, the effects ofER on adults who use English as a foreign language (EFL) has rarely been addressed. Hence, the purpose of this study is to investigate the impact of ER on Taiwanese EFL working adults' English reading attitudes. We invited five females working at a university to participate in ER activities for 12 weeks. The participants were given graded readers to read. Data on their reading experiences were collected through semi-structured interviews, questionnaires, and reading logs. Results of the data analyses showed that the participants' reading attitudes turned more positive and participants became more interested in English reading at the end of the 4- month period. Participants' comments indicate that the availability of appropriate levels of reading material is vital to the effectiveness of ER. Guidance on material selection and ER strategies should be provided to learners to enhance their reading effectiveness.