We investigated, in 20 patients with Graves’ disease and presenting with both a surgically induced hypothyroid state and increased serum antibodies (Ab) to the TSH receptor (R) levels, the relationships between thyroid status and the serum TSH-R or peroxidase (TPO) Ab levels under L-T₄ treatment and after L-T₄ cessation. The prevalence of positive TSH-R Ab (100%) and the log mean TSH-R Ab level (1.41 ± 0.04%) observed during the surgically induced hypothyroid state decreased (p < 0.001, p < 0.01, respectively) under L-T₄ therapy (prevalence of positive TSH-R Ab = 50%, log mean TSH-R Ab level =1.21 ± 0.05%) and increased again (p < 0.001) after L-T₄ cessation (prevalence of positive TSH-R Ab = 85%, log mean TSH-R Ab level = 1.45 ± 0.06%) to reach levels lower ( < 0.01) than that observed during the hypothyroid state for prevalence of positive TSH-R Ab but similar to that obtained during such a state for log mean TSH-R Ab value. The log mean TPO Ab level obtained during the surgically induced hypothyroid state (3.2 ± 0.5 titer) decreased (p < 0.02) under L-T₄ therapy (1.8 ± 0.2 titer) and increased again (p < 0.02) after L-T₄ cessation (3.0 ± 0.5 titer) to reach a similar level to that obtained during the surgically induced hypothyroid state. There were positive correlations between log TSH levels and log TSH-R Ab values (r = 0.40, p < 0.001) or log TPO Ab levels (r = 0.33, p < 0.01). Likewise, negative correlations (p < 0.01) were found between FT₄ values and log TSH-R Ab levels (r = -0.34) or log TPO Ab values (r = -0.31). In conclusion, our results suggest that thyroid hormonal status can modulate thyroid autoimmunity expression, such as serum TSH-R and TPO Ab levels in hypothyroid patients with Graves’ disease.