This study examines how artificial intelligence (AI) chatbots influence the conversational proficiency of English as a Foreign Language (EFL) learners. Conversational proficiency—defined as the ability to speak fluently, use appropriate vocabulary, apply correct grammar, and pronounce words accurately—is essential for effective communication but often poses challenges for EFL learners. AI chatbots, leveraging natural language processing to simulate human dialogue, provide a unique opportunity for learners to practice speaking in a supportive, low-stakes setting. In this research, 50 intermediate-level EFL learners participated in a 12-week intervention, engaging in daily conversations with an AI chatbot tailored for language learning. Pre- and post-intervention assessments evaluated improvements in fluency, vocabulary, grammar, and pronunciation. Findings revealed significant gains in fluency and vocabulary, alongside moderate progress in grammatical accuracy. However, pronunciation improvements were minimal, reflecting the chatbot’s limitations in delivering detailed phonetic feedback. Learners also reported greater confidence and reduced speaking anxiety, underscoring the psychological benefits of AI-supported practice. Nevertheless, the study highlights that AI chatbots struggle to replicate the cultural nuances and contextual depth of human conversation. These results suggest that AI chatbots serve as an effective supplementary tool for enhancing specific elements of conversational proficiency, particularly when paired with traditional instruction. The study concludes by advocating for a hybrid approach to language education that integrates AI technology with human interaction to support holistic language development, while proposing future research into enhancing chatbot capabilities for pronunciation training and sustained proficiency growth.