This study aims to investigate reading strategies and factors affecting the use of strategies of Thai EFL English majors enrolled in public and private universities in Bangkok. The participants were 482 college students and the study used both quantitative and qualitative analysis. In addition to using the questionnaire adapted from The Survey of Reading Strategies (SORS) questionnaire (Mokhtari and Sheorey, 2002), think-aloud protocols, retrospective interviews, and document study were used. The quantitative results demonstrated that the participants used a combination of reading strategies but the problem-solving strategies seemed to be the most reported strategies used. Overall, the factors affecting the use of reading strategy were the instructional type and the self-rated reading ability type. In addition, qualitative data showed that the English proficiency levels, the years in school, the opportunity to use English, and the instructional type affected the participants' strategy use.