The current study was conducted to investigate the effect of task-based and topic-based speaking activities on improving the speaking ability among Iranian EFL learners. The study used quasi-experimental design. The subjects consisted of 60 male and female students who were selected from among 90 EFL learners by applying the nelson proficiency test. 30 subjects formed a control group which received conventional method. The other with 15 subjects formed experimental group A which received the task-based speaking activities. Another 15 formed the experimental group B which received the topic-based speaking activities. Oral interviews were used both as the pretest and posttest in order to evaluate the speaking proficiency of subjects before and offer the treatment, the results indicated that task-based speaking activities enhanced speaking ability of Iranian EFL learners, but not significantly enough to reject the stated null hypothesis.