Improving English language skills among santri in pesantren is a challenge that requires innovative approaches, such as bilingual programs. This study aims to analyze the effectiveness of bilingual implementation in improving the English language skills of santri in pesantren. The research method involved statistical evaluation of reading and writing test scores and questionnaire responses in measuring the impact of the program, complemented by thematic analysis of the qualitative data to identify key themes related to program implementation and effectiveness. The reading test results showed that 75% of the santri achieved ‘Good’ to ‘Very Good’ scores, signaling strong reading comprehension. However, the writing test results showed that no santri achieved a ‘Very Good’ score, although 35% of santri scored ‘Good’ and 43% scored ‘Fair,’ indicating proficiency in writing mechanics, grammar, and vocabulary. The perspective of the santri regarding the bilingual program was also positive, with the majority agreeing or strongly agreeing with the program's effectiveness. The implications of this study suggest that while the bilingual program effectively improves reading skills, there needs to be further focus on developing writing skills. Suggestions for future research include longitudinal research and a broader evaluation of language skills to gain a holistic view of the effectiveness of the bilingual program.