This study looked at 128 secondary school biology teachers aged 23 - 34 in Hanoi and Dien Bien to ascertain their knowledge and personal opinions about reproductive health. It was found that 68.4 percent of the teachers had a good level of knowledge about reproductive health with no difference between teachers in Hanoi and Dien Bien. Unfortunately, only 39.7 percent fully understood the mechanism and usage of contraception methods, with teachers in Dien Bien scoring slightly higher than those in Hanoi (P 0.05). It was found that 99.2 percent of the teachers in Dien Bien were aware of the causes, symptoms and prevention of HIV/AIDS and sexually transmitted infections (STIs) while only 43.7 percent of the teachers in Hanoi were aware. Most of the teachers accept the current State guidelines on family planning and the Law on Marriage and Family. Many teachers in Dien Bien were not even aware of the concept of gender equality. These findings point directly to the need for teacher reeducation in the areas of contraception, sexually transmitted disease and gender equality.