Project-based learning (PBL) is one of most common teaching strategies in design education. With the complexity in design projects, PBL is usually accomplished in groups. The final project success depend on both technical capabilities and individual personalities: personality types and communication styles. Although previous studies have investigated the relationship between personalities and project success, the relationship between the composition of personalities and project success among design students has yet to be examined. Student personalities were studied based on students' response to the personality assessments, Myers-Briggs Type Indicator (MBTI) and the four-type communication model. Project success was recorded in both PBL and individual learning processes for comparisons. Results show that project success is positively correlated with group compositions that have a balanced proportion of Judging (J) and Perceiving (P) members, and negatively correlated with compositions that have an even proportion of Extrovert (E) and Introvert (I) members. Results also show that group compositions that have members with leadership qualities (the Rational temperament and the Director communication style) are more likely achieve success. Comparisons between project success in PBL and individual learning processes indicate that students with specific personalities (the Guardian and the Relator) perform significantly better in individual assignments than group assignments. The purpose of this study is therefore two-fold; first, to study how the different compositions of personalities could explain group dynamics and influence project success and second, to highlight that PBL might be more suitable for some students than others. This study concludes that with an understanding of students' personalities, teachers can create groupings to maximize the potential of PBL and, at the same time, provide individual learning activities to enable equal opportunities for all students to achieve success.