Background: The coronavirus disease 2019 (COVID-19) pandemic is affecting people at any age and there is limited information about the effect of the COVID-19 pandemic on quality of life (QoL) in adolescents with asthma. In the present study, it was aimed to assess the attitudes of adolescents with asthma toward the COVID-19 pandemic and determine the effects of the pandemic on their QoL. Methods: In total, 125 adolescents with asthma and 98 healthy adolescents participated in the present study. The questionnaire form consisted of three parts. In the first part, all the participants were asked whether they complied with the protective measures against COVID-19. The second part included questions for measuring the participants' level of concern about COVID-19, while the third part consisted of EUROHIS-QOL 8. Results: The patient and control groups were similar in terms of the female/male ratio (55/70 and 48/50, respectively) and mean participant age (14.6 +/- 2 and 15.1 +/- 1.65 years, respectively) (P = 0.459 and P = 0.062, respectively). The prevalence of COVID-19 in the patients (n = 2, 1.6%) was lower than that in the controls (n = 6, 6.1%); however, the difference was not statistically significant (P = 0.142). The total EUROHIS-QOL score was significantly lower in the patients (31.2 +/- 6.7) than in the controls (33.7 +/- 4.4) (P < 0.001). The total QoL scores of asthmatic adolescents without other allergic disease (31.4 +/- 6.7) was also lower than those of the controls (33.7 +/- 4.4) (P = 0.009). Treatment disruption was significantly more common in patients who received subcutaneous immunotherapy (n = 20, 48.8%) than in those who did not (n = 8, 9.5%) (P < 0.001). Moreover, the patients had lower EUROHIS-QOL scores in the overall QoL, general health, finance, and home domains. Conclusion: Our results indicate that the mean QoL score of asthmatic adolescents during COVID-19 pandemic is lower than in the healthy population. Disruption in their treatment was most common in patients with asthma who were receiving subcutaneous immunotherapy.