Several past studies of EFL learners' reading strategies have focused either on the strategies they used for learning to read or on those they used for taking tests. However, studies that distinguish the reading strategies used by EFL learners for learning-to-read purposes from those used for test-taking purposes in the target language, and that focus on the probable hierarchy of language learning strategies, have not been found. This study attempted to address these research gaps in the rarely studied EFL context of Thai undergraduates. One hundred and thirty-five Thai undergraduates were categorized based on reading test scores into high and low proficiency readers. Then, a questionnaire, five multiple-choice and 22 5-point Likert scale items, was administered to identify reading strategies for learning to read and for taking tests that distinguished the two groups. All significant learning-to-read and test-taking strategies were then ordered based on degrees of mean differences to determine the hierarchy. The data were analyzed with descriptive statistics and tests of statistical significance (p < 0.05). The results showed the top learning-to-read and test-taking strategies that significantly distinguished the high proficiency from the low proficiency readers were affective and cognitive strategies, respectively. The findings shed light on significant cultural consideration for EFL strategy-based reading instruction.