The most important thing when dealing withpathogens is quick, effective and accurate diagnosis. Traditional methods require many hours of culturing and are gradually being replaced by molecular biology and biochemistry tools, involving techniques like PCR, electrophoresis, hybridisation or green fluorescent protein (GFP) marking. The aim of this study was to determine whether real-time PCR may replace the traditional method of surface cultures of environmental samples and when it should be used. The analysed samples came from various stages of wastewater treatment processes. The amount of indicator organisms’ cells like Salmonella typhinmurium or Clostridium perfringens was determined. The method was also tested for “emerging” organisms such as Escherichia coli 0157:H7 and for “new” bacteria like Yersinia enterocolitica or Legionella pneumophila. The DyNAmo HS SYBR Green qPCR Kit was used as a fluorochrome. It was noted, that wastewater treatment processes significantly influenced reduction of quantity of studied microorganisms, however do not eliminate them, hence wastewater and sewage sludge may still be an important reservoir of pathogens. The real-time PCR is highly sensitive method, although isolation of DNA not only form alive cells of microorganisms, could resulted in high false positive results.