This poster paper presents an overview of the Åbo Akademi full-scale boiler ash behavior measurement database. The database contains data from some 20 full-scale boiler measurement campaigns during which the ash behavior in the boiler has been monitored identically. The measurements have been done in 3 different bubbling fluidized bed boilers and 2 circulating fluidized bed boilers during 11 different campaigns. For comparison data from 2 pulverized fuel fired boilers as well as from 2 grate fired boilers have also been included. The data collection includes conventional analyses of the fuels or fuel mixes used during the measurements, ash deposition measurements performed with the air-cooled probe technique, chemical analyses of the collected deposits (front and back side separately, chemical analyses of the boiler fly ashes, and recordings of chosen relevant boiler operation parameters such as boiler load, air-distribution, and flue gas temperatures. The poster paper presents ash deposition data, so called Rate-of-build-up values (RBU, g/m2h) as a function of fuel mixes, probe surface temperatures and boiler type. The poster also presents compositional data of the collected deposits such as the chlorine content as a function of fuel mix and probe surface temperature.