Graves' disease and Hashimoto's thyroiditis are autoimmune thyroid disorders with distinct pathological and histopathological features. The conversion from Hashimoto's thyroiditis to Graves' disease has been rarely reported throughout the world with no reports in the African race to our knowledge. We here report an African lady who was initially diagnosed with primary hypothyroidism following Hashimoto's disease but later became thyrotoxic due to Graves' disease.