This study is a quasi-experimental, longitudinal investigation into the role that extensive reading and reading strategies play in the cultivation of reading self-efficacy. Conducted over the course of one academic year, how changes in reading self-efficacy translate into changes in reading comprehension was examined. In addition, the participants' perceptions of the utility of extensive reading and reading strategies, and how those perceptions related to reading self-efficacy were investigated. A final goal was to ascertain how retrospective ratings of reading self-efficacy influence current levels of the construct. The participants (N = 322) were first and second-year, non-English majors at a four-year, co-educational university in Osaka, Japan. The participants were divided into four groups: an intensive reading group (control group), an extensive reading group, a reading strategies group, and an extensive reading/reading strategies group. Data for the study were obtained from six major sources: a reading comprehension test, a reading strategy test, a reading self-efficacy questionnaire, a perceived utility of extensive reading questionnaire, a perceived utility of reading strategies questionnaire, and a sources of reading self-efficacy questionnaire. The questionnaires and tests were administered three times over the course of the academic year. Before conducting the quantitative analyses on the data gathered with the above instruments, the dichotomous test and questionnaire data were analyzed using the Rasch rating-scale model to confirm the validity and reliability of the instruments and to transform the raw scores into equal interval measures. By employing MANOVAs, ANOVAs, Latent Growth Curve Modeling, and Pearson correlation coefficients, the data were then analyzed to ascertain differences between groups and within groups for all tests and constructs measured. The results showed that the participants in the reading strategies and extensive reading/reading strategies groups gained significantly more in reading self-efficacy over the academic year than those in the extensive reading and intensive reading groups. In addition, all three experimental groups outperformed the intensive reading group in reading comprehension. Furthermore, results from the latent growth curve model showed that gains in reading self-efficacy were related positively to gains in reading comprehension. In a similar vein, the results showed that gains in reading strategy skill led to changes in reading self-efficacy, while reading amount was not significantly related to changes in reading self-efficacy. The results also suggested that those who more highly regard extensive reading as useful to improving reading comprehension exhibited higher levels of reading self-efficacy over the course of the study. On the contrary, there was no significant difference in levels of reading self-efficacy between those who highly rated reading strategies as useful and those who did not rate them as highly. Finally, Pearson correlation coefficients showed moderately strong relationships between junior high and high school (retrospective) levels of reading self-efficacy and university (current) levels. These results underscore the importance of self-efficacy in the learning process and how the cultivation of self-efficacy should be a goal of any educator or administrator in an EFL context. The findings also highlight the detrimental effects of teaching methodologies, such as grammar-translation, that deprive learners of the opportunity to develop their own cognitive abilities. With the introduction of reading strategy intervention and/or extensive reading practice, the participants in the experimental groups of this study were able to develop the skills needed to overcome comprehension breakdowns in the reading process, and this help them become more autonomous, empowered readers.