||Previous research has investigated college adjustment and personality, but this is the first study to investigate Big Five traits as predictors of college adjustment using a prospective design and personality ratings from well-acquainted informants. In the present study, 109 high school seniors completed the revised NEO Personality Inventory (NEO-PI-R) and 83 of them returned to complete the Student Adaptation to College Questionnaire (SACQ) near the end of their freshman year. Personality ratings were also gathered from parents ( n = 77) and peers ( n = 81). Neuroticism was significantly correlated with SACQ Personal-Emotional and Total scores. Extraversion and Agreeableness were significantly correlated with SACQ Social scores. Conscientiousness was significantly correlated with SACQ Academic scores. Ratings by parents provided incremental prediction of academic adjustment and ratings by peers provided incremental prediction of social adjustment. The findings of this study may enable institutions to identify and assist students who may experience difficulty adjusting to college.