This study measured social anxiety and its impact on academic achievement. To measure the rnparticipant's level of social anxiety, an instrument called Social Phobia Inventory Test/ Scale rn(SPIN) was used. The data was analyzed using SPSS version 24. Based on this scale, 124 rnparticipants were found socially anxious. t-test, Pearson correlation and percentage were used rnto analyze the data. Results showed that social anxiety correlated negatively and significantly rnwith academic achievement. Participants were 267 randomly selected students by using lottery rnmethod from 3 grade levels (grade 10th -12th) at Kidist Sellassie Cathedral Secondary School rn.The sample comprised 133 males and 134 females. Academic achievement and academic task rnavoidance are positively correlated. The academic achievement of socially anxious groups are rnlow first semester average scores (negative relationship between social anxiety and average rnscores) this implies that non-socially anxious groups performed academically better than the rnsocially anxious groups. And results show that social anxiety correlated positively with academic rntask avoidances.