The floods of the first half of the year of 2010 in our country have revealed to us again the importance of probability of failure calculations of soil dikes. In this case we have to find an effective routine like the Monte Carlo analysis, which was developed for modeling multiple problems using random variables. In the situation of soil dikes the random variables are the soil parameters, geometrical parameters and loads. Each variable can be defined by its statistical parameters and distribution, so first we must determine the factors that we would like to build into our calculation, and next we have to define them with the aid of statistical analysis. The practice of probability of failure calculation in areas of geotechnology is not wide-spread so it is hard to find any commercial software, which could solve the global problem. The article shows an example of the probability of failure calculation for a homogenous dike section.