We present the first description of organic-walled microfossils from Cambrian strata of the Bourinot belt, central Cape Breton Island. Age-diagnostic acritarchs have been recovered from the Dugald and MacMullin formations and from probable levels within the upper part of the Eskasoni Formation, which permit detailed correlations with acritarch-based zones in Newfoundland and Spain. The assemblage of acritarchs from the Dugald Formation confirms earlier assignments to the early middle Cambrian eteminicus Zone, but it also indicates that the upper part of the formation belongs to the hicksi Zone of the Drumian Stage. Acritarchs from the MacMullin Formation provide the first biostratigraphic evidence that this unit extends into the forchhammeri Zone of the Guzhangian Stage. These acritarchs are present in the lower part of the MacMullin Formation, putting into question earlier identification of hicksi Zone trilobites in this unit and raising the possibility of an unconformity. The data from the Bourinot belt provide additional evidence for the biostratigraphic utility of acritarchs in the Cambrian Acado-Baltic province.