This study aimed to investigate the effectiveness of practicing English conversations with ChatGPT to enhance speaking skills of English as a Foreign Language (EFL) learners at Nguyen Tat Thanh University, specifically focusing on four key criteria: conversational fluency, pronunciation, vocabulary use, and grammatical accuracy. In this study, 60 students were divided into six groups for a quasi-experimental design with a combination between non-equivalent groups design and pretest-posttest design. Four groups were trained with ChatGPT for eight weeks, while two control groups were not. Speaking abilities were measured through pretest, mid-test, and posttest assessments. The findings revealed significant improvements in conversational fluency, vocabulary, and grammar for the ChatGPT-trained groups, while pronunciation showed minimal progress. These results suggest that integrating ChatGPT into English teaching curricula could help non-English majored students at Nguyen Tat Thanh University enhance their English communication skills.