The purpose of this retrospective study was to evaluate the diagnostic accuracy of CT-fluoroscopic transthoracic biopsy of pulmonary lesions related to their localization and size. The complication rate was also evaluated. Between January 2003 and June 2004, we performed seventy-two CT-fluoroscopic transthoracic biopsies in sixty-nine patients. Lesions were subdivided in subpleural, peripheral and central lesions. The lesions were also subdivided concerning their diameter. Fifty three lesions (77%) had a final diagnosis of malignancy and 13 lesions (19%) had a final benign diagnosis. CT-fluoroscopic transthoracic biopsy had an overall diagnostic accuracy of 84.4%, sensitivity of 80.7%, specificity of 100%, positive predictive value of 100% and negative predictive value of 54.5%. For lesions between 1 and 3 cm the accuracy was 78.5% for lesions greater than 3 cm 87%. Only one lesion was smaller than 1 cm, this lesion was true positive. There were no false-positive findings. Pneumothoraces were observed in only 7 patients (10%) and there was only 1 small postpuncture hemothorax (1.7%). CT-fluoroscopic biopsy of pulmonary lesions has a good diagnostic accuracy with a very low complication rate. The accuracy is higher for larger lesions, but there is no significant difference for subpleural and peripheral lesions.