<p>The microstructure of unsaturated soils plays a vital role in their hydromechanical behaviour. The study investigates the changes in tensile strength with microstructure for a clayey soil upon drying. Five compaction water contents (12.5%, 14.5%, 16.5%, 18.5%, and 20.5%) defining different initial soil microstructures were considered. Tensile strength was directly measured at various degrees of drying, along with the determinations of water content, degree of saturation and suction. Microstructure characteristics at as-compacted and dried states were analysed by mercury intrusion porosimetry. The results indicate that soil specimens on the dry side and at the optimum water content exhibit a bimodal pore size distribution, characterized by macropore and micropore populations, while soil specimens on the wet side have a unimodal distribution with one micropore population. After drying, the frequency of micropores decreases, while the frequency of macropores remains unchanged (on the dry side and at the optimum) or slightly increases due to shrinkage cracking (on the wet side). Upon drying, tensile strength increases with decreasing water content or degree of saturation due to suction effects. Soil specimens with both micropores and macropores develop lower suction than those with only micropores and are prone to tensile failure at the macropores (between aggregates). Consequently, when subjected to the same degree of saturation or suction, wet-side specimens exhibit significantly higher tensile strength compared to dry-side specimens. A theoretical model accounting for the microstructural differences was developed to describe the tensile strength of unsaturated soil. This model was validated against experimental data.</p>