The influence of micro-organisms on degradation of mineral materials, cement bound systems, wood and steel is a rather new subject of research slowly becoming recognised by the 'classical' technical disciplines. An increasing amount of literature appears on biodeterioration of construction materials and microbial activity can not be neglected as a determining factor in the deterioration process. Microbial communities interact in many different ways with mineral materials and their external environment. They can be present on the surface or in crevices and fissures within the material and often their actions become organized in a biofilm. The interaction with the material and its environment can give rise to biodeterioration. Yet recent findings show that in some cases the microbial interaction can lead to protection of materials. It is our mission for the future to engineer the microbiological processes with positive impact on construction materials with a view to practical applications.