In my thesis I would like to give a survey and comparison of the rituals (especially the fertility rituals) of those Native American tribes that live in the Southwest and the Plains cultural regions. [...] To achieve the goal of this paper, I pursued the following purpose: I briefly present the religious customs and rituals that are more or less in the same form present in the greater part of the tribes examined, first according to regions and treated separately, then in the last chapter I treat them together, making comparisons and drawing general conclusions about the causes of aforementioned similarities and differences, thus creating starting points for a possible further research. I would also like to create a theory and prove it using data gathered during the writing of the thesis.