Because 83% of adolescent pregnancies among teens 15 to 19 years old are unintended and because adolescents with chronic medical conditions are as likely to be sexually involved as are healthy teens, preventing unintended pregnancies among teens with chronic endocrine conditions, including diabetes mellitus (both types 1 and 2), PCOS, and thyroid dysfunction, is critically important. Evidence-based guidelines are available to assist with assessment of the risks versus the benefits of specific options for contraception in teens with these and other medical conditions. In many teens, including those with chronic medical conditions, the top-tier contraceptive methods--implants and intrauterine devices--represent the most effective, safest, and most successful contraceptive options for adolescents. Prepregnancy counseling can be an important tool for managing chronic endocrine conditions and lowering the risks for both mother and fetus, but it is underutilized among all women, particularly adolescents. The management of pregnancies complicated by DM, PCOS, and thyroid conditions is facilitated by a coordinated effort among obstetricians, endocrinologists, dietitians, and nurse educators. Primary physicians should be aware of their potential role in preventing unplanned pregnancies among all adolescents, but particularly among those with chronic medical conditions.