It is argued that task-based instruction creates more favorable conditions and facilitates L2 acquisition. For this reason task-based language teaching has recently been the focus of the attention of many L2 language instructors and syllabus designers. The main purpose of this paper is first to discuss the current views and three schools of syllabus design and then review three kinds of task-based syllabi: A) Procedural Syllabus B) Process Syllabus and C) Task-Based Language Teaching. Finally, the results of a classroom research in which two groups have been taught under different approaches will be presented. Preliminary results of statistical analyses revealed that task-based language teaching led to greater fluency and complexity than structural-based language teaching, as reflected in greater number of Words per Pause and greater number of Lexical Density. But the result ran counter to our hypotheses in terms of accuracy. Structural-based language teaching approach led to greater accuracy than task-based language teaching, as reflected in greater number of Error-Free T-Units. Pedagogic implications are discussed.