Primary dysmenorrhea is the most commonly encountered menstrual issue among adolescents, often leading to significant school absenteeism. This study aimed to detect the impact of primary dysmenorrhea on adolescents’ activities and school attendance. We conducted a cross-sectional comparative study involving 180 adolescents aged 12 to 18 who experienced primary dysmenorrhea. A comprehensive trans-abdominal pelvic sonography was performed to rule out any underlying pelvic conditions. The severity of dysmenorrhea was evaluated using the visual analog scale (VAS), categorizing adolescents into groups with mild dysmenorrhea (VAS ≥1 to ≤3), moderate dysmenorrhea (VAS >3 to ≤7), and severe dysmenorrhea (VAS >7 to ≤10). Adolescents were surveyed to determine whether the severity of dysmenorrhea had an adverse effect on their physical and social activities as well as their school attendance. We used one-way ANOVA to compare the groups. There was a significant positive relation between the severity of dysmenorrhea and its negative impact on adolescents’ physical activities (r=0.395; p<0.00001) and social activities (r=0.658; p<0.00001). Additionally, there was a significant positive relation between the severity of dysmenorrhea and its negative impact on adolescents’ school attendance (r=0.416; p<0.00001). The odds of a negative impact on adolescents’ physical and social activities and school attendance were significantly higher in adolescents experiencing moderate and severe dysmenorrhea than in adolescents with mild dysmenorrhea.