The authors present their experiences with 185 computed tomography (CT)-guided needle placement procedures in 146 consecutive patients. There was 100% accuracy in first-bypass entry into the lesion using a needle guide; 100% success in drainage of intracranial abscesses; 100% success in palliative decompression of intracranial cystic lesions including tumor cysts; and 97% accuracy in histologic diagnosis of unknown lesions. CT-guided aspiration biopsy corrected clinically incorrect diagnoses and altered patient management in 23% of all cases biopsied. Tabulation of complications revealed 0% incidence of scalp infection, bone infection, dissemination of tumor, or dissemination of infection; 13.5% incidence of clinically insignificant postprocedural bleeding; and 0.5% incidence of serious postprocedural hemorrhage leading to death (one patient only). Transient hemipareses were observed in three of 22 procedures for implantation of 192Ir but in none of 163 procedures for aspiration biopsy alone.