The timing and stability of the decision to enter a medical specialty were examined for one class of medical students. Students were asked to predict specialty choices for themselves on six occasions from orientation day in year 1 to January of the senior year. Choices were compared to actual National Residency Matching Programme results. Forty-five per cent predicted their ultimate specialty choice at orientation, and 69% predicted their ultimate choice by the end of the second year. Specialty choices are made early, and are more stable and accurate than the previous literature has suggested. Variations in timing among the specialties are described, and implications for medical education are discussed.