Background: Thyroid gland is a endocrine gland that secretes thyroxine (s.T3), triiodothyronine (s.T4) under the effect of TSH (thyroid stimulating hormone). Synthesis and secretion of hormones are dependent on negative feedback mechanism. Objectives. The objective of our study were to determine and assess the correlation between serum ferritin and thyroid hormone levels among hypothyroid and euthroid subjects. Materials and methods: A cross sectional study was conducted on 100 patients with a history of hypothyroidism diagnosed based on their TSH levels, age group between 20-60 years. Samples collected from patients visiting Medicine OPD, IGIMS, Patna. with clinical symptoms of hypothyroidism tested for s. ferritin, s.fT3, s.fT4 and s.TSH were considered for the study.