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Objective: To describe the magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) features of the orbital rhabdomyosarcoma (RMS).Methods: Thirty-nine patients with histopathologically proven orbital RMS were retrospectively reviewed.All patients underwent orbital conventional MRI, including axial, sagittal and coronal Tl-weighted sequence, T2-weighted sequence and postcontrast Tl-weighted sequence.The location, shape, margin, and MRI signal of the 39 lesions were reviewed.DWI in 5 patients and susceptibility weighted imaging (SWI) in 2 patients were also analyzed.Results: All lesions were unilateral.33 lesions were well-defined soft tissue masses and 6 lesions appeared as less well-defined soft-tissue masses.34 lesions showed homogeneous isointense or slightly hypointense signals on Tl-weighted imaging (T1WI) and hyperintense signal on T2-weighted imaging (T2WI) compared with extraocular muscles.5 lesions had heterogeneous signals with focal areas of increased signal on T1WI or decreased signal on T2WI, including 1 lesion with hypointense signal on SWI.The mean apparent diffusion coefficient (ADC) value of the viable part of tumors was (0.923 ± 0.09)× 10-3 mm2/s.All lesions showed moderate to marked enhancement after contrast administration.28 patients had extraocular muscle invasion and 8 patients had extraorbital invasion.Conclusion: Some important MRI features including homogeneous isointense or slightly hypointense signal on T1WI and slightly hyperintense signal on T2WI, relative low ADC values, moderate to marked enhancement, extraocular muscles invasion, and extraorbital extension are helpful in the diagnosis of orbital RMS in pediatric patients.