Arbuscular mycorrhizal fungi (AMF) are obligate symbiotic microorganisms that form associations with a variety of plant species and are found in several biomes, such as the Brazilian Caatinga. This study aimed to determine the diversity, richness and distribution of AMF communities in four areas with different soil textural classes and vegetation type in the Caatinga. Nine soil and root samples were collected during the dry season in each area, totalling 36 sampling units. In total, 45 AMF species were recorded, with a predominance of the genera Acaulospora and Glomus. The highest species richness was observed in Open shrubby Caatinga, with a loamy sand textural class, which had higher density of glomerospores. A higher rate of mycorrhizal colonization was observed in ‘Brejo de altitude’, i.e. a mountain top rainforest, with sandy clay loamy soil. Soil texture was the main determining soil factor in structuring the AMF communities in the areas in addition to other factors—fine sand, coarse sand, phosphorus, hydrogen, aluminium, aluminium saturation and base saturation— were also important in determining the composition of the AMF communities in the areas studied.