Forensic serology plays a crucial role in criminal investigations by identifying body fluids such as blood, semen and saliva at crime scenes. This process provides essential DNA evidence, establishing connections between suspects, victims and crime scenes, thus adding significant context that strengthens the overall evidence. In legal proceedings, DNA evidence alone may be insufficient because it does not indicate the nature of the crime. Therefore, determining the specific type of body fluid is particularly significant as it can provide critical information, such as confirming whether a violent act or sexual assault occurred. Presumptive tests, known for their sensitivity, offer rapid initial indications of body fluids, making them invaluable for quickly screening extensive crime scene areas and identifying potential biological evidence that may not be visible. In contrast, confirmatory tests are highly specific, targeting unique markers of body fluids to ensure accurate identification. Together, these methods ensure the reliability and integrity of forensic evidence, ultimately supporting the pursuit of justice. Presumptive tests for blood, saliva and semen, along with confirmatory tests such as immunochromatographic assays and microscopic analysis, are discussed in detail in this chapter, highlighting their crucial role in forensic investigations. This chapter further explores the challenges of identifying body fluids and the importance of integrating these methods with DNA profiling to enhance the reliability of forensic evidence in legal contexts.