The in vivo concentration of lysophospholipids (LPL) such as lysophosphatidylcholine (LPC) increases under different pathological conditions and, thus, LPL attract nowadays considerable diagnostic and pharmacological interest. LPL are particularly interesting because they possess pro- and anti-inflammatory properties and can be generated by two completely different pathways: either by the influence of (a) phospholipases and (b) different reactive oxygen species (ROS) that are generated in significant amounts under inflammatory conditions. This review provides a summary of the mechanisms by which LPL can be generated under in vitro and in vivo conditions. The focus will be on lysophosphatidylcholine (LPC) because this LPL is most abundant among all LPL and was, thus, most intensively studied so far. Additionally, biochemical, chromatographic and spectroscopic methods of LPL and LPC determinations will be discussed. Finally, the effects of LPL as signaling molecules and their roles in different pathologies such as infertility, cancer, atherosclerosis or inflammatory diseases are discussed. Special emphasis will be on the role of LPL in reproduction failures related to poor semen quality and, in that context, the potential role of LPC as a disease-indicative molecule.