Clinical characteristics of tumors metastatic to the orbit are related to primary tumor biology, and vary substantially among the various primary types. Common known primary sites include breast, lung, prostate, and melanoma. Tumor presentations can be classified into four generalized syndromes of mass, infiltrative, inflammatory, and functional effects. We found the infiltrative syndrome of presentation to be more common than for other types of orbital neoplasm. Accurate diagnosis often depends on recognition of the types of clinical syndromes and on the use of diagnostic modalities such as computed tomography, magnetic resonance imaging, fine needle aspiration biopsy, and open biopsy. Special histologic techniques are often useful in determining the origin of these often poorly differentiated tumors, and can provide a basis for specific hormonal therapy. Ophthalmologists play a vital role in the diagnosis of metastatic cancer; the orbital tumor was the presenting sign of systemic cancer in 42% of the cases reviewed. Although the overall prognosis for patients with metastatic cancer is quite poor, specific therapy is available for a growing number of cancers. Timely intervention based on accurate diagnosis can dramatically improve the duration and quality of life with selected tumors.