Purpose: To report a rare case of rhabdomyomatous mesenchymal hamartoma and to compare its features with those cases previously reported. Design: Interventional case report and literature review. Intervention: Complete ophthalmologic and systemic examinations followed by excisional biopsy and histopathologic examination. Main Outcome Measures: Clinical examination features and histopathologic findings. Results: A 6-month-old Latino male presented with a congenital, elevated, smooth, flesh-colored right lower eyelid lesion. An ipsilateral right limbal dermoid and an upper eyelid coloboma were also present. Excisional biopsy of the eyelid lesion revealed randomly oriented mature striated muscle tissue with associated adipose tissue, blood vessels, pilosebaceous units, and peripheral nerves, findings consistent with rhabdomyomatous mesenchymal hamartoma. Of the 24 reported cases (including the current case), eight had associated congenital anomalies. Conclusions: Although rhabdomyomatous mesenchymal hamartomas are rare and benign, they may be associated with other congenital anomalies and anomaly syndromes. As a result, we recommend systemic evaluation of patients diagnosed with this entity. © 2001 by the American Academy of Ophthalmology.