OBJECTIVE: The purpose of this article is to investigate potential technical, imaging, and histopathologic contributors to the success of CT biopsy. MATERIALS AND METHODS: Four hundred forty-four consecutive CT biopsies of musculoskeletal lesions performed from 2005 to 2008 were retrospectively classified as diagnostic or nondiagnostic and as accurate or inaccurate. A biopsy was considered as diagnostic if it provided a definitive pathologic diagnosis or was clinically useful; as accurate if it was concordant with the ultimate diagnosis with respect to identification of malignancy, grade, and histopathologic features; and as successful if it was both diagnostic and accurate. Biopsy success rate, diagnostic yield, and accuracy were assessed according to lesion location, use of sedation, biopsy equipment type, bone lesion matrix type, and lesion histologic type (i.e., bone or soft-tissue origin, malignant or benign neoplasm, and low-or intermediate-to-high-grade neoplasm). RESULTS: Of 444 biopsies, 71% were diagnostic, 86% were accurate, and 70% were successful. Biopsy success and diagnostic yield were greater in bone lesions, malignant neoplasms, and intermediate-to-high-grade neoplasms compared with soft-tissue lesions (p < 0.01), benign neoplasms (p < 0.0001), and low-grade neoplasms (p < 0.0001). Success and diagnostic yield were not significantly associated with technical or imaging factors. Biopsy accuracy was not associated with any of the tested variables. Of the 128 nondiagnostic biopsy results, 53% were accurate with respect to subsequent surgical pathologic findings. Most of these biopsy results were of benign soft-tissue lesions. CONCLUSION: CT biopsy of musculoskeletal lesions is accurate and effective. It may be limited in the evaluation of benign and low-grade soft-tissue neoplasms.