This research aimed to study the use of Project-based Learning using ICT (PBL using ICT) to develop learners' five key competencies based on Thai Basic Education Curriculum 2008, which consists of 1) communication capability 2) thinking capability 3) problem solving capability 4) capability in applying life skills and 5) capability in technological application. The subjects were 212 students from 4 schools in Kanchanaburi, Chiang Mai, Mae Hong Son, and Si-Saked provinces that were enrolled in the 2010 academic year. The PBL using ICT approach was used as the research tool. The data collecting instruments were lesson plans, students' journals, semi-structured interviews, and social networking where students' learning artifacts and products were collected (nectecpbl.ning.com). Content analysis and triangulation methods were used to analyze the data. The results showed that students were able to perform five key competencies in communication capability, thinking capability, problem solving capability, capability in applying life skills, and capability in technological application. Moreover, the students learned the content in the learning areas of Science, Mathematics, Foreign Languages, Health and Physical Education, and Occupations and Technology. The research findings revealed that the use of PBL using ICT can help to develop students' abilities to communicate ideas, problem solving, life skills, and abilities to use technology, as well as their learning in content of the subject area.