DNA was extracted from urinary sediments and was sufficient for polymerase chain reaction (PCR) and enzymatic analysis, even if DNA from microorganisms coexisted. From urine samples, the yield of DNA ranged from trace levels to 20 micrograms per 10 mL urine. When urinary sediment was stored in ethanol, DNA remained stable for 2 weeks or more. Individual identification and sex determination could easily be performed using either fresh or ethanol-fixed urine. In conclusion, urine can be used as a source for PCR-based investigations and genetic studies.