For the etiological diagnosis, history, physical examination, and additional tests (TSH, free thyroxine, thyroglobulin, bone age assessment, thyroid ultrasound) were carried out in the first visit. Results: The etiology was established in the first visit in 53.3% of cases. Thyroid dysgenesis represented 51.11% of the cases, from which 20% showed hypoplastic thyroid, 13.3% showed athyreosis, and 17.7% showed ectopic glands; 2.2% were diagnosed with dyshormonogenesis. Umbilical hernia was the most prevalent sign (48.89%) and 20% had no clinical manifestations. Patients with dysgenesis showed significant differences (p < 0.05) in terms of cesarean section delivery, delayed bone age, and very high serum TSH. Conclusions: The diagnostic approach used at first visit for PCH patients may determine the etiology in 53.3% of cases. Half of patients had thyroid dysgenesis. Arq Bras Endocrinol Metab. 2012;56(9):627-32