In a consecutive series of 33 patients (38 biopsies), the authors analyzed the pathologic specimens obtained with their relatively new transvenous biopsy method. From the point of view of establishing a useful pathologic diagnosis, the method proved worthwhile in the series of predominantly critically ill patients. A specific diagnosis or a later confirmatory tissue diagnosis was achieved in 18 patients, and a strong clinical correlation was achieved in 10 more. There were no complications from this repeatable, technically relatively simple, and safe procedure.