Medical students applying to residency positions in obstetrics and gynecology often have strong geographical preferences. For training programs in obstetrics and gynecology, the distribution of categorical PGY-1 resident positions per million people was analyzed for each American College of Obstetricians and Gynecologists (ACOG) district. Data were obtained from the 2000 U.S. census and the 2003 resident match. The data indicate that the number of PGY-1 residency training positions per million people in the United States varies by geographical region. The fewest PGY-1 residency training positions per capita are in the West. In the 2003 match, Districts VIII and IX, respectively, offered 2.1 and 2.8 PGY-1 residency positions per one million people. The greatest number of PGY-1 positions per capita are in the East. Districts I, H, and a respectively, offered 5.7, 8.0, and 5.3 PGY-1 residency positions per one million people. Many factors are likely to contribute to the observed geographical differences. A correlation coefficient of 0.81 (P < .01) was observed between population per square mile in each ACOG district and the number of PGY-1 positions per million people. Low population density likely limits the development of residency programs in some geographical areas. To allow medical students as much geographical choice as possible, additional residency positions could be developed in the West if educational opportunities and clinical needs support such a change. (C) 2004 by The American College of Obstetricians and Gynecologists.