Fluorescence diagnosis and photodynamic therapy with 5-aminolevulinic acid induced protoporphyrin IX are promising new options in the diagnosis and therapy of diseases in a wide spectrum of medical disciplines such as urology, dermatology, gastroenterology, surgery, neurosurgery and gynecology. The techniques are based on the application of the heme biomolecule precursor 5-aminolevulinic acid which induces the endogenous accumulation of the photosensitizer protoporphyrin IX in designated tissues. After external excitation with blue light a strong red fluorescence can be initiated particularly in tumorous tissues. In gynecology many studies have been performed evaluating the usefulness of fluorescence based detection of cervical dysplasias, breast cancer, endometrial diseases, ovarian cancer and endometriosis. This work aims on the principles of fluorescence detection as an important tool in biomedical optical imaging and its current status in gynecology.