Probability is an important topic in the high school mathematics curriculum. However, dealing with randomness is always a challenge for Vietnamese students because they have not been encouraged to use their intuitive abilities and they lack the experience needed to feel the likelihood of probabilities. To overcome this difficulty, it is necessary to use simulation in the teaching and learning probability at school. This paper would like to introduce Monte Carlo simulation which is a method of solving probability problems through the use of experiments. This method should be used in teaching probability to high school students because it increases their practical experience and it teaches students how to apply probability when attempting to solve real world problems. This paper explains what Monte Carlo simulation is and why and how teachers should teach Monte Carlo simulation to high school students.