Students who have good or at least average intellectual abilities and could definitely perform better at school, but do not live up to their potential and do not demonstrate adequate academic achievement are referred to as academic underachievers. In Thailand, the Ministry of Education has recently declared 2009 the year of student development and improvement. Consequently, a significant attention has been focusing on the issue of academic underachievement including the proclamation of the Student Supporting System for Learner Development. The system has been employed in order to systematically help students solve their problems in various aspects including underachievement. The topics in this article include concept of academic underachievement, characteristics of academic underachieving students, factors associated with academic underachievement, and directions of underachievement. Finally, the system for dealing with academic underachieving students in Thailand has been presented.