Introduction: The aim of this study was to compare happiness and willingness to communicate in attachment styles in sample students in University of Tabriz.Method: Using cluster sampling, 400 students were selected and for data collection, Hazan and Shaver Attachment Styles Scale and Memorial University of Newfoundland Scale of Happiness (Munsh) and Willingness to Communicate Scale were used. Data analysis using one-way analysis of variance and the post hoc multiple comparisons were performed.Results: The results showed that there are significant differences between attachment styles and happiness. Students with secure attachment style had a higher happiness than non-secure students with avoidant and ambivalent attachment styles. Students with avoidant attachment style had higher happiness than those with ambivalent attachment style. Another result showed that there are significant differences between attachment styles and willingness to communicate.Conclusion: Students with secure attachment style had higher willingness to communicate than non-secure students and students with ambivalent attachment style had higher willingness to communicate compared with avoidant students. Overall, attachment styles affect happiness and willingness to communicate.