Objective To explore the safety and efficacy of frameless stereotactic brain biopsy.Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frameless stereotactic brain biopsy between January 2008 and December 2010 in Xiamen University Southeast Hospital.Preoperative characteristics and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and complications.Results Diagnostic yield was 93.5%.No differences were found between pathological diagnosis and frozen pathological diagnosis.The most common lesions were astrocytic lesions,included 16 cases of low-grade glioma and 12 cases of malignant glioma.Remote hemorrhage,metastasis,and lymphoma were following in incidence.Multiple brain lesions were found in 17 cases (27.4%).Eleven cases were frontal lesions (17.7%),8 were frontotemporal (12.9%),6 were frontoparietal (9.7%),and 5 each were temporal,parietal,and parietotemporal lesions (8.1%).Postoperative complications occurred in 21.0% of the patients after biopsies,including 10 haemorrhages (16.1%) and 3 temporary neurological deficits (1 epilepsy,1 headache,and 1 partial hemiparesis).No patient required operation for hematoma evacuation.Conclusion Frameless stereotactic biopsy is an effective and safe technique for histologic diagnosis of brain lesions,particularly for multifocal and frontal lesions. Objective To explore the safety and efficacy of frameless stereotactic brain biopsy. Methods Diagnostic accuracy was calculated by comparing biopsy diagnosis with definitive pathology in 62 patients who underwent frameless stereotactic brain biopsy between January 2008 and December 2010 in Xiamen University Southeast Hospital. Preoperative characteristics and histological diagnosis were reviewed and then information was analysed to identify factors associated with the biopsy not yielding a diagnosis and complications. Results Diagnostic yield was 93.5% .No differences were found between pathological diagnosis and frozen pathological diagnosis. the most common lesions were astrocytic lesions, included Sixteen cases of low-grade glioma and 12 cases of malignant glioma. Remote hemorrhage, metastasis, and lymphoma were all found in 17 cases. Multiple brain lesions were found in 17 cases (27.4%). Eleven cases were frontal lesions (17.7%), 8 were frontotemporal (12.9%), 6 were frontoparietal (9.7%), and 5 eac h were transient, parietal, and parietotemporal lesions (8.1%). Postoperative complications occurred in 21.0% of the patients after biopsies, including 10 haemorrhages (16.1%) and 3 temporary neurological deficits (1 epilepsy, 1 headache, and 1 partial hemiparesis) .No patient required operation for hematoma evacuation. Confc Frameless stereotactic biopsy is an effective and safe technique for histologic diagnosis of brain lesions, particularly for multifocal and frontal lesions.