The present research was an attempt to provide new evidence for the efficacy of task-based techniques to speaking proficiency development. The primary focus of the study was to investigate the effects of task-based techniques on speaking proficiency development. In the second place, it tried to scrutinize the effect of gender on speaking proficiency development under task-based principles of language teaching. In better words, the study is an attempt to find out which gender group would become more proficient in speaking after the task-based course came to an end. The study also tried to put possible different effects of task-based approach on foreign language learners of different levels of language proficiency under focus. Accordingly, the participants were categorized into two categories of 81, as the control and the experimental groups of the study. In continuation, each category was divided into two groups of males and females and finally, each male and female group of each category was classified into two classes of intermediate and advanced. In this way, each of the control and the experimental group contained some intermediate and some advanced male and female language learners .In order to determine whether task-based techniques to teaching speaking were effective and also to figure out which gender and proficiency level had a higher degree of improvement in speaking under task-based approach, a set of independent sample t-tests were conducted. Furthermore, in order to comment on the possible interaction between gender and different levels of language proficiency, a two-way ANOVA (MANOVA) was also conducted. It was found that the students of the experimental group, who experienced task-based principles of teaching speaking, performed remarkably better than those of the control group on the final speaking post-test. It was also concluded that gender was not a determining factor in speaking development under task-based approach but difference in language proficiency levels was shown to be an influential factor in speaking development since advanced language learners of the experimental group had performed ostensibly better than those of intermediate learners of the same group on the final speaking post-test. Ultimately, it was deduced that there was not a meaningful interaction between gender and different levels of language proficiency for a better development of speaking ability. In other words, it was not possible to determine a specific pattern of interaction between them by their simultaneous presence in the study.