Thyroid carcinoma is the most common malignancy of the endocrine system and it accounts approximately 1%-3% of all human cancers. Among the three subtypes of thyroid cancers, medullary thyroid carcinoma (MTC) is the most common cause of death in patients with multiple endocrine neoplasia (MEN) type 2A (MEN2A), MEN type 2B (MEN2B) and familial medullary thyroid carcinoma (FMTC). Generally, MTC accounts for up to 10% of all types of thyroid cancers. It is one of the aggressive forms of thyroid carcinoma which is manifested in childhood ages more than adults, and it comprises about 17% of all pediatric thyroid cancer. Like the other cancers, prevention of MTC is easier than its cure. In the recent decades (from 1993) the diagnosis of asymptomatic child carrying RET mutations in the affected families by MTC, has been provided by genetic screening, and prophylactic thyroidectomy is an efficacy therapeutic procedure. On the one hand, according to near the complete penetrance of the disease and its onset in the early years of life, it is required to accelerate the protection of at-risk children with relative affected by MTC and on the other hand, there are several obstructions to MTC treatment including: 1) the proband's refusal to disclose the RET mutation genetic testing results, 2) children's vulnerability because of their inability to participate in the informed consent, and 3) the existence of conflict between physicians and children's guardian. In this review article, the recommendations and ethical issues of MTC treatment in asymptomatic and at-risk children have been summarized.