In view of their widespread occurrence in the environmental segments, these are considered as ubiquitous. The incomplete burning of different substances cause their generation and distribution in environment, particularly air. Smaller PAHs such as naphthalene are relatively less toxic compared to higher members such as benzo[a]pyrene, which is carcinogenic in nature. At places, it is reported that PAHs contamination is also present in the drinking water, causing direct harm to the humans. The most toxic effect is their involvement with the DNA and formation of DNA adducts, which results is mutations and sometimes can cause cancer. The dominant PAH pollution mechanism can be differentiated by the application of diagnostic ratios like phenanthrene/anthracene or fluoranthene/pyrene ratios. These ratios suggest the nature of PAH pollution is major from petrogenic or pyrogenic sources. The PAHs from the soil can be transported to roots of the plants and slowly reaches to other parts of the plants including fruits and vegetables. Without any metabolic activation, oxygenated PAHs and nitrogenated PAHs can bind with DNA directly and cause mutations, posing severe threat to living organisms. Various detection and remediation techniques have been applied for the detection of PAHs in various environmental matrices. This chapter gives a basic overview of the ubiquity, sources, distribution, fate, derivatives, transport, detection and remediation of PAHs.