IN THE PAST FEW YEARS, a great deal of interest has been focused on the problem of distinguishing true bacteriuria from contamination. The normal urethra is known to harbor bacteria which may contaminate specimens obtained either by voiding or by catheterization. The latter method of obtaining samples may well be the means of introducing organisms that might not have been present before or of replacing sensitive with resistant organisms. Moreover the risk of producing such an infection is greater with the incompletely emptying bladder of lower urinary tract obstruction It has been suggested that percutaneous needle aspiration of the bladder urine may not only be safer than catheterization in some circumstances, but would also obviate contamination of samples during voiding or catheterization. Elsewhere in this issue, Nelson and Peters relate their experience with suprapubic percutaneous aspiration of the urinary bladder in premature and full-term neonates. Aspiration of bladder urine for bacteriologic purposes was first reported in 1956 by Guze and Beeson, who compared colony counts in urine samples obtained both by bladder aspiration and catheter in a small group of women free from urinary tract infection. The following year a comparison of bacterial counts of the urine obtained by needle aspiration of the bladder, catheterization, and midstream collection was described by Manzon and her associates. In 1959 we obtained samples of urine by percutaneous needle aspiration of the bladder and compared the quantitative cultures with those obtained immediately thereafter by catheterization; all these samples were from infants and children prior to elective laparotomies.