The study aims at estimating the relationship between mindfulness and the social anxiety in a sample of adolescents. The analytic descriptive approach has been used in the study. The participants consist of 150 male and female students in the first and second years at the Faculties of Arts and Education in Port Said University, whose age ranges from 17 to 20 years. This is conducted using the mindfulness scale (Beer et al., 2006) translated by Muhammad Al-Sayed Abdel Rahman (2015), the social anxiety scale (Liebowitz, 2000) codified by Ibrahim Al-Shafei (2018). The results of the study show that there is a statistically significant negative correlation at the level of 0.05 between the scores of mindfulness and social anxiety among a sample of adolescents. They also show that there are statistically significant differences between males and females with regard to mindfulness and the differences are in favor of males, while the differences in social anxiety are in favor of females.