Young people's exposure to social networks such as Facebook is growing everyday. At the same time there is a growing number of studies that examine the role of Facebook in romantic relationships. Attachment and sociosexuality were in previous studies often examined in the context of traditional offline jealousy. Recently, more and more researchers are exploring jealousy in the context of social networks, in this research, Facebook, so called modern jealousy. The main purpose of this research was to examine the differences in Facebook jealousy, dimensions of attachment (anxiety and avoidance) and sociosexuality considering sex and relationship status and to establish the correlation between them. The study was conducted on a sample of 226 participants of which 41 male and 185 female students. Moreover, considering relationship status, on a sample of 226 participants 52 of them were single, 147 were in a committed relationship with one person while 27 participants were occasionally seeing one or more person. For the purposes of this research, three scales were applied: Facebook Jealousy Scale, Relationship Structures (ECR-RS) Questionnaire and Revised Sociosexual Orientation Inventory. Most of the world's researches have revealed that women are more prone to Facebook jealousy than men but difference was not found in this research. Difference between men and women was not established on either of the dimensions of attachment while on the scale of sociosexuality men scored higher scores and were described as sociosexually unrestrictive while women were described as sociosexual restrictive. Single people were more prone to Facebook jealousy than people who are in serious, committed relationship with one person while other differences in Facebook jealousy were not found. Single people and those who are occasionally seeing one or more person scored higher scores on anxiety and avoidance than those who are in committed relationship with one person. Difference between single people and those who occasionally are seeing one or more person was not established. On a scale of sociosexuality, people who are occasionally seeing one or more person scored the highest score and were described as sociosexually unrestrictive. On the other hand, those who are in committed relationship with one person scored the lowest score and were described as sociosexually restrictive. Facebook jealousy was positively correlated with anxiety, negatively correlated with sociosexuality while correlation between Facebook jealousy and aviodance was not found. Sociosexuality was negatively correlated with avoidance while the correlation between sociosexuality and anxiety was not found. Facebook jealousy is area of research which is still relatively new suggesting the need for further theoretical and applied researches. The results could serve to therapists in dealing with clients because of the negative consequences of Facebook jealousy.