Background and Objective: This study aimed to investigate the relationship between the use of mobile based virtual social networks with academic achievement and  trust in interpersonal relations of university students Of Medical Sciences was conducted.

Materials and Methods: This study was descriptive correlational. The study population included college of Public Health students and students of medicine at Birjand University of Medical Sciences. Based on purposive sampling method, 150 students were selected. For data collection Scale of trust in interpersonal relations of Rempel & Holmes was used. The researchers made use of social networks and academic achievement. Data were analyzed by SPSS software version 20.

Result: There was a significant negative relationship between the time allotted to the network and the number of virtual  memberships  in social groups and academic achievement of students(P <0.01). Academic achievement of students who used virtual social networks for scientific purposes was higher than those who used it for non-scientific purposes.  There was a significant negative correlation between the time allocated to social networks and factors such as capability of trust, predictability and loyalty (P <0.05).

Conclusion: It is recommended that workshops and training courses be held for practical learning of virtual networks.