Pregnancy is a favorable condition for thyroid nodule formation and growth since iodine balance may be negative in addition to increasing production of hormones with thyroid stimulatory activity. Thyroid nodules may be discovered in pregnant women on routine examination: what is the risk for a nodule to be malignant, how should it be investigated? In case thyroid cancer is suspected, is there an impact of pregnancy on the tumor outcome and what treatments are available? Infrequently, diagnoses of toxic autonomous nodules or medullary carcinomas may be supported by elevated serum calcitonin or suppressed TSH value. Ultrasonography scanning and fine-needle aspiration biopsy (FNAB) best help to monitor thyroid nodules and guide their management. Toxic autonomous nodules can be either surgically resected in the second trimester of pregnancy or treated by percutaneous alcohol injection. When cytology findings are benign or indecisive, solid nodules require follow-up by neck palpation, in association to repeat ultrasonographic study and nodule aspiration as necessary. In this setting, thyroxine administered in small doses or iodine supply merit consideration. If FNAB samples are suggestive of suspicious or malignant lesions, thyroidectomy can be performed through the second trimester or delayed after delivery, depending on the pregnancy term. Observations of pregnant women with a rapid growing differentiated thyroid cancer have been reported. However, in matched studies comparing pregnant and nonpregnant women recurrence risk and cancer mortality are not significantly different.