The emergence of social networks has not just had a great impact in the way companies promote their products and services, but also in the decision-making process of consumers regarding their purchases. Using the application and extension of the models proposed by Okazaki et al. (2012), the present study tries to understand the factors that motivate the use of social networks in the purchase decisions of young university students, for this a self-administered questionnaires were applied to 224 university students. Some limitations were found at the time of evaluating the adjustment of the model through a structural equations method, due to the number of indicators per construct. However, the results show that the proposed model presents a good adjustment. Therefore, it can be concluded that the study develops an appropriate approach to the knowledge of the factors that can influence university students, who intend to use social networks to buy, validating the conclusions drawn by Okazaki et al. (2012) in their study. At last, it is recommended for companies that wish to promote their products through social networks to look out for strategies that combine information transparency and stimulation of word-of-mouth communication among users, generating a larger impact on the purchase decisions of clients.