With the occurrence of the web, online social network sites have emerged, which have flooded our lives for communication purposes. They are primarily intended for communication and self-presentation of users, which can be honest or positive. Use and further self-presentation of the individual are driven by motivation. It can be intrinsic or extrinsic, based on the literature and empirical research, the purpose of the thesis is to find out how different motivations affect the level of honest self-presentation of a registered user on the Reddit online social network. By regression analysis of the data obtained from the publication of the survey on major subreddits in 2017, I found that both intrinsic and extrinsic motivation positively influence the degree of honest self-presentation on social network sites. The same was noted in the qualitative part in which five semi-structured interviews were analyzed.