Detailed analysis of literature on late Devonian and Carboniferous acritarchs learns that, up to now, late Devonian acritarch zonation has been proposed only for Algeria, U.S.A. and Belgium. These zonations comprise only part of the Upper Devonian sequence in U.S.A. and Belgium, whereas the complete Upper Devonian acritarch zonation for Algeria is not matched by a detailed chronostratigraphic subdivision for that last area. Upper Devonian and Carboniferous acritarchs have also been described from many other areas in North and South America, Africa, Europe, Asia and Australia, but the data are mainly based on spot sampling or these are restricted to rather reduced intervals.Comparison between the abundance of acritarchs in late Devonian sequences of Ohio and Belgium reveals consistent patterns of successive maxima and minima. They may reflect global changes in the environment and be related to worldwide events. Remarkable is the extremely low number of acritarchs throughout the Carboniferous succession. This forms a clear contrast with the relative abundance of acritarchs in marine Devonian sediments.