Abstract: This study responds to the international widespread application of content-based instruction in foreign/second language teaching as well as the recent calls in Bahrain to promote literacy skills within the learning of English as a foreign/second language (EFL/ESL). The study achieves this through exploring the effectiveness of using designed content-based tasks in developing 97 Bahraini students’ literacy skills while learning EFL/ESL within a design-based research project as an initiative to support their school’s attempt to improve the general performance in learning English and respond to the quality assurance standards required in this regard. The main findings indicate the efficiency of the designed content tasks in developing the students’ literacy skills while learning EFL/ESL on different levels; development of cognitive and learning habits, language proficiency improvement and reinforcement of self-confidence as foreign/second language users. The study discusses these outcomes with their implications for the language learning as well as for possible future language policy in EFL/ESL instruction in Bahrain.