This study explored the current job-related problems faced by beginning teachers, their teaching effectiveness, and professional performance in Taiwan. Additionally, it analyzes the difference between teachers at different teaching stages and in different teaching areas. This study used the Ministry of Education’s database of 104 school year beginning teacher survey. The sample population included 1,621 Taiwanese beginning teachers. The major results present the following: First, the main challenges faced by beginning teachers in teaching are the differentiation of student levels and how to facilitate student learning. Second, beginning teachers in different education stages and teaching areas show significant differences in terms of job problems, teaching effectiveness, and professional performance. Third, the job problems and teaching effectiveness of beginning teachers can predict their professional performance.