Smartphones are indeed becoming an essential tool in the daily lives and relations of their users in recent years, thanks to their uses and potential. However, excessive and inappropriate use can lead to dependence syndromes. The objectives of our study were to ascertain how these devices are being used and whether students are at risk of addiction. The study was carried out based on a survey with students--future teachers--from two Spanish universities. A sample of 453 students between the ages of 18 and 47 was analyzed, 76.8% female and 23.2% male. Smartphones were found to be the preferred Internet connection device for 80% of students, 38% of students connect to the Internet five hours or more a day (which can be considered an addiction) and smartphones are used primarily to connect with others (social media and instant messaging). The abusive use of smartphones affects men's behavior more than women and can lead them to neglect other activities, while smartphones affect women more in the emotional field, in matters related to boredom, impatience, and irritability.