Water- and vector-borne diseases are a global burden which is estimated to cause several million deaths and innumerable cases of sickness every year. These infectious illnesses are emerging or resurging as a result of several factors, such as changes in climate, in public health and demography policy, as well as the spread of resistance to insecticide and drug, and genetic changes in pathogens. Integrated prevention strategies must be developed and implemented in endemic disease areas to reverse the trend of emergent/resurgent water- and vector-borne diseases. With this perspective porphyrins and their analogues, that have been shown to act as very efficient photosensitising agents against a broad number of microbial pathogens (bacteria, fungi, protozoa) and parasitic animals, could represent an important tool for the prevention and control of these pathologies. The application of photosensitised processes can be exploited to address environmental problems of high significance, including the decontamination of waste waters, the disinfection of fish-farming tanks and the control of populations of noxious insects. Such diversified applications take advantage of the availability of a truly large number of porphyrin derivatives with chemical structures which can be tailored to comply with the physical and chemical properties, as well as the biological features of several milieus. In addition, the property typical of porphyrins to absorb essentially all the wavelengths in the sun emission spectrum allows the promotion of processes largely based on natural resources with significant energy saving and low impact on the ecosystems.