© Cocuk Cerrahisi Dergisi. All rights reserved.Objective: An in vitro study was designed to evaluate the antibacterial activity of desmopressin (DP), oxybutynin (OX), imipramine (IP), and doxazosin (DX), which are used commonly in enuresis treatment. Material and Methods: To investigate the antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis; the drugs were dispensed to tubes with physiologic saline (PS) or brain-heart broth (BHB). BHB was followed for 6 days and PS for 20 days. Antibacterial activity was examined using in vitro Time-kill method. Bacteria colonies were counted daily from PS and BHB media as colony-forming units (CFU) and evaluated by bacteri-growth graphs. Results: In BHB, none of the drugs affected growth of any bacteria. In PS, E. coli growth increased initially with DP, DX and IP and then decreased on the 5th day. Growth of E. coli was seen to continue in PS without drug on the 5th day. For DX and IP, S. epidermidis growth in PS first increased then decreased. In all PS media, growth of P. aeruginosa was seen to increase gradually. Conclusion: DP, DX and IP decreased growth of E. coli in PS, but did not prevent bacterial growth completely. Drugs used in enuresis treatment have no antibacterial activity for the bacteria evaluated in the current study.