The purpose of our research was to study gender differences in competition between friends among young Hungarian adults. We were asked 345 college and university students - 161 men and 184 women - for their opinions related to rivalry between same-sex friends, and for their own behavioural intentions in different competitive situations. In order to achieve our goal we have developed a questionnaire based on our own method. The questionnaire contained six situations where friends could compete with each other for different purposes. These purposes were: sexual partner, material goods, intellectual superiority, sport achievement, social acceptance and career opportunity. In each situation subjects were asked to assess reactions given by the investigators as to how much they accept them, how likely they think other people could choose them as possible behaviour and to choose one reaction which is appropriate for them. Results unequivocally confirm the theories which consider competition a very important and sometimes unavoidable factor in the friendship of persons of the same gender. The quality of the competition appearing in different situations is determined by many factors. An important factor is the person's gender, which in most cases influenced the different answers in interaction with the situational and personality factors, for example the person's disposition to competition. Our results show the peculiarity of the difference between the competition of men and women. We have not found any certain proof of the common theory that women see representatives of their own sex as being more competitive than men, and that women do not undertake competition openly in their behaviour. The results reflect the interactive influence of gender and other factors, an interaction in which the influence of the person's gender has a dynamically changing direction and intensity.