Background: Adolescent anemia is a global public health concern, disproportionately affecting low- and middle-income countries. Despite this burden, Türkiye lacks a national screening or supplementation program targeting this age group. Aim of the study: The aim of the study is investigating the etiological spectrum and clinical characteristics of anemia in adolescents aged 10–18 years referred to a tertiary pediatric hematology clinic in Türkiye.Material and methods: This retrospective study evaluated 356 adolescents diagnosed with anemia at Bursa City Hospital between August 2020 and September 2023. Demographic, clinical, and laboratory data—including serum iron, ferritin, vitamin B12, and folate levels—were analyzed. Anemia was defined per WHO thresholds.Results: The mean age was 14.07 1.96 years, with 81.5% being female. Iron deficiency anemia (IDA) was the most prevalent etiology (74.4%). Borderline or overt vitamin B12 deficiency was detected in 27.8%, and folate deficiency in 8.7%. Combined nutritional deficiencies were present in 24% of patients. Genetic anemias, particularly beta-thalassemia trait (14.9%), were also observed. Approximately 23.6% were asymptomatic at diagnosis, and excessive menstrual bleeding was a common contributor among girls. IDA was significantly associated with older age and female gender (p<0.001).Conclusions: Nutritional deficiencies—especially iron, vitamin B12, and folate—remain the leading causes of adolescent anemia in Türkiye. The high rate of asymptomatic cases and coexisting micronutrient deficits underscore the need for national, age- and gender-sensitive screening and supplementation strategies. These findings may support the development of targeted, age- and sex-sensitive screening and nutritional assessment strategies for adolescents, particularly in high-risk clinical populations.Background: Adolescent anemia is a global public health concern, disproportionately affecting low- and middle-income countries. Despite this burden, Türkiye lacks a national screening or supplementation program targeting this age group. Aim of the study: The aim of the study is investigating the etiological spectrum and clinical characteristics of anemia in adolescents aged 10–18 years referred to a tertiary pediatric hematology clinic in Türkiye.Material and methods: This retrospective study evaluated 356 adolescents diagnosed with anemia at Bursa City Hospital between August 2020 and September 2023. Demographic, clinical, and laboratory data—including serum iron, ferritin, vitamin B12, and folate levels—were analyzed. Anemia was defined per WHO thresholds.Results: The mean age was 14.07 1.96 years, with 81.5% being female. Iron deficiency anemia (IDA) was the most prevalent etiology (74.4%). Borderline or overt vitamin B12 deficiency was detected in 27.8%, and folate deficiency in 8.7%. Combined nutritional deficiencies were present in 24% of patients. Genetic anemias, particularly beta-thalassemia trait (14.9%), were also observed. Approximately 23.6% were asymptomatic at diagnosis, and excessive menstrual bleeding was a common contributor among girls. IDA was significantly associated with older age and female gender (p<0.001).Conclusions: Nutritional deficiencies—especially iron, vitamin B12, and folate—remain the leading causes of adolescent anemia in Türkiye. The high rate of asymptomatic cases and coexisting micronutrient deficits underscore the need for national, age- and gender-sensitive screening and supplementation strategies. These findings may support the development of targeted, age- and sex-sensitive screening and nutritional assessment strategies for adolescents, particularly in high-risk clinical populations.