The objective of the study was an attempt to produce spontaneous sourdoughs from wholegrain flours made from common wheat, spelt wheat, and rye. In the flours analyzed, the following was determined: water content, ash, selected mineral components, total protein, raw  fat, dietary fibre, selected mycotoxins, and myo-inositol phosphates. Moreover, there were determined fat acidity, potential acidity, falling  number as well as the content of gluten and gluten index. Using every type of the wholegrain flours tested, sourdoughs were produced;  they were, further, monitored for 4 days by determining the active acidity (pH) and titratable acidity. In comparison to flours made from  common wheat and rye, the wholegrain spelt wheat flours were distinguished by higher contents of protein, fat, and mineral compounds;  however, they had less total fibre. All the wholegrain flours (except MO1 spelt flour) were characterized by a similar content of myoinositol phosphates in the form of IP₆ and IP₂, but only the rye flour was additionally distinguished by the IP₅ and IP₃ forms.  Mycotoxins, i.e. DON and zearalenone, were not found in any wheat flours except for the MO1 spelt flour, in which trace amounts of  zearalenone were identified. Sourdoughs produced from the wholegrain spelt flour after the 72 h fermentation at 30 ºC were characterized  by a greater acidity compared to those produced from the wheat flour and their acidity was more similar to that of the rye sourdoughs.  Thus, all the types of sourdough obtained can be used to produce bread from 100 % wholegrain flour made from rye, spelt, and common  wheat.