There may be several reasons -for being involved in reading of any kind, such as reading -for survival or reading -for pleasure» This study is particularly concerned with reading which serves to extend our general knowledge o-f the world in the academic context. Efficient reading is a challenging task in itself, even -for the native speaker» The need -For efficient reading skills becomes mare crucial in cases where the medium of education is English? that is, the foreign-language context. The general purpose o-f the study is to investigate the factors which are likely to be determinants of success in reading comprehension in a foreign language. The basic assumption of this study is that there are certain reader characteristics which contribute to and interact with the reader's performance on certain assessment devices. Student's reading comprehension ability in English is examined by taking into consideration the following aspects of the foreign-language reading phenomenon, the text (its content, structure, and language), the appropriateness of the text to the student's prior knowledge, the task demands of the assessment devices and the sources of answers to questions, the reading ability of the student in the native and target language, and the student's foreign language proficiency. Subjects of this study were 370 students attending the one- year preparatory English program at the University of Gaziantep» The analysis of the data showed that English-language proficiency was a stranger predictor of success in reading in English rather than the subject's reading ability in the native language» The study also supports the hypothesis that reader's f ami 1 iarity with the text content significantly affects his/her success on two types of comprehension measures, namely the multiple-choice comprehension test and the written recall protocols» but not an the vocabulary test» Subjects were also observed to be better- able to answer inferencing and generalization types of questions when the text content was a familiar one» Written recall protocols revealed supportive evidence to the hypothesis that when the content matter of the passage is familiar subjects recall more idea units »elaborate more on the topic» and make fewer distortions in their recalls following the reading» Another conclusion that was drawn from the study is that students at all levels of linguistic proficiency benefit from text familiarity» Chapter I provides a brief preview of the direction that reading theories have taken, together' with the various definitions of the reading and comprehension processes that have developed from those theories» A more thorough account of the reading theories, and relevant research in the field is included in chapter II to shed light on the theoretical bases of this study» Information regarding the way the study was carried out, the instruments that were used, and how the data were evaluated can be found in chapter III in complete detail» Chapter IV i i reveals the results of the study in statistical and descriptive terms and points out to statistically significant relationships among the various -factors that are hypothesised to be interacting during the reading process. In chapter V the data are analysed and interpreted? each hypothesis that was initially put forward is evaluated and discussed on the bases of the support it receives from the results of the present study» Final conclusions are drawn and suggestions are made for potential teachers of English who will be teaching reading» and/or who will be construction measures to assess reading comprehension» or yet who will be judging the appropriacy of a given instrument under certain conditions» Suggestions for further research accrues from the researcher's experiences and observations throughout the study» m.