This study investigated the effects of attachment styles of university students on their social skills and loneliness levels. Their social skill levels, loneliness levels and attachment styles were measured by the Social Skills Inventory, UCLA Loneliness Scale, and Relationships Scale Questionnaire respectively. To analyze data, t-test, correlation analysis, and regression analysis were employed. Emotional expressivity, levels, emotional sensitivity levels, social control levels, and total social skill levels of female students were found to be significantly higher than those of male students. However, emotional control levels of male students were significantly higher than those of female students. A significant effect of attachment styles on loneliness and social skills was detected. Social skill levels of students who have secure attachment styles were found to be significantly higher than social skills levels of students who have insecure attachment styles. Average loneliness points of students who do not have a romantic relationship were found to be significantly higher than others. However, the average social skill points of those students were found to be significantly lower than others.