The objective of the research study was to determine the effect of ultrasounds on the microstructure of osmo-treated and dried sour cherry fruits. The ‘Nefris’ sour cherry fruit variety was osmotically dehydrated using a 60 % sucrose solution for 120 min. (40 ºC) in an ultrasonic bath equipped with a transducer (25 kHz, 0.4 W/cm²) and a shaking platform (30 rpm). The total time of osmotic dehydration was 120 min; during that time period, diverse time variants of ultrasound (US) treatment and shaking (S) were applied. First, the samples were treated by ultrasounds (US) for 0, 30, 60, 90, and 120 min.; next, they were shaken for 120, 90, 60, 30, or 0 min., respectively. The dehydrated fruits were convectively dried. The structure of osmo convectively dried samples of dehydrated fruits and raw material was microscopically analyzed. It was confirmed that the application of ultrasounds caused changes in the structure of tissues. A longer time of exposing sour cherry tissue to ultrasounds resulted in a decrease in the density of cells directly adjacent to the epidermis. Concurrently, it was found that the deformation of parenchyma cells increased and the intercellular spaces faded away. By the most homogenous structure (the most elongated and circular cells) were characterized the dried fruits that were osmo-treated and, simultaneously, ultrasound-treated and shaken for 60 min. (60US+60S); thus the presence of optimal state was proved that supported the reduction in internal tension. The convective drying causes the tissue to considerably contract. In the dried fruits, which were not treated by ultrasounds, but only shaken for 120 min. (0US+120S), alternating free intercellular and highly compact spaces were found. The application of ultrasounds for max 60 min. caused the homogeneity of structure of the material being dried to increase (optimal variant: 6US+60S).