To determine the underlying factor structure of the Japanese version of the Posttraumatic Growth Inventory (PTGI-J), a principal components analysis was performed on data from 312 Japanese undergraduate students who reported growth due to their most traumatic event within the last 5 years. Results showed the PTGI-J has high internal consistency and, of the original five factors reported by Tedeschi and Calhoun (1996), three were replicated: Relating to Others, New Possibilities, Personal Strength, and a fourth factor integrating Spiritual Change and Appreciation of Life emerged. There were neither gender differences nor relationships with time since trauma. PTGI-J scores were positively associated with posttraumatic symptoms and correlated with type of traumatic event experienced. These results and future directions are discussed from a cross-cultural viewpoint.