For patients with thyroid cancer taking anticoagulants, because of hematoma risk at the injection site, intramuscular injections (IM) of recombinant human thyrotropin (rhTSH) are usually avoided and patients remain hypothyroid. The aim of the present study was to evaluate if subcutaneous injections (SC) of rhTSH are an alternative to IM. Five consecutive patients receiving anticoagulants were evaluated. The dose regimen was similar to the traditional follow-up protocol (2 x 0.9 mg, SC route). rhTSH administration elicited a sharp and prompt increase in serum TSH that peaked at day 3 (24 hours after the second rhTSH injection), with mean values of 246 +/- 68 mU/L. In one patient with a large thyroid remnant, thyroglobulin (Tg) rose from 18 ng/mL to 450 ng/mL. No adverse effects were observed. We conclude that SC injection of rhTSH represents a safe and efficient procedure in the monitoring of patients with thyroid cancer taking anticoagulants.