While, indirect ophthalmoscopy is unquestionably the most useful in the diagnostic approach to retinoblastoma, a variety of imaging modalities such as ultrasonography, fluorescein angiography, CT, MRI, and more recently, OCT, ultrasound biomicroscopy can be useful ancillary studies to confirm the diagnosis of retinoblastoma and differentiate retinoblastoma from lesions that simulate retinoblastoma. Retcam™ photography and fluorescein angiography are useful tools in addition to indirect ophthalmoscopy to diagnose, document and monitor retinoblastoma. Ultrasonography is a noninvasive effective tool to determine the presence of calcification. Computerized tomography scan is valuable in determining the presence of calcification but should be avoided keeping in mind the risk of radiation exposure. Magnetic resonance imaging is a useful adjunctive tool especially for diagnosing optic nerve and choroidal infiltration. It is also useful for monitoring for tumor recurrence after enucleation and for neuroimaging in retinoblastoma patients.