We assessed the prevalence of testicular microlithiasis by scrotal ultrasonography in β-thalassemia major patients older than 10 years and evaluated the association with serum ferritin levels, calcium (Ca), phosphate (Ph), and parathyroid hormone levels (PTH). In this cross-sectional study, 132 male β-thalassemia major patients from 300 male patients older than 10 years old were randomly evaluated by scrotal ultrasonography. Parathyroid hormone, calcium, phosphate, and serum ferritin levels were also evaluated. All of the patients were urologically asymptomatic. One hundred healthy age-matched subjects were selected as control group. Testicular microlithiasis was found in 16 patients and 1 individual in control group (12.1 vs 1 %; p = 0.003). Testicular microlithiasis was associated with age and high serum ferritin levels, but there was no association between Ca, Ph, and PTH levels; blood transfusion; and oral or subcutaneous iron chelation therapy. Also, there was no significant correlation between hyperparathyroidism, history of viral hepatitis, and splenectomy with testicular microlithiasis. The frequency of testicular microlithiasis in β-thalassemia major patients was higher than previously reported. A correlation was found between testicular microlithiasis with age and serum ferritin levels, so regular and adequate iron chelator therapy (at least 10-12 h per day for 5-6 days a week) is recommended. We suggest a close observation and treatment with iron-chelating agents of these patients. Since testicular microlithiasis is occasionally associated with germ cell tumors, clinical and sonographic follow-up is recommended.