Resorcinol-formaldehyde aerogels were synthesised using acid-catalysed polycondensation of resorcinol and formaldehyde in acetonitrile or dimethyl sulfoxide, followed by supercritical drying in CO2. The structure and mechanical properties of the aerogels were analysed using low temperature nitrogen adsorption, scanning electron microscopy, small-angle neutron scattering and stress-strain measurements in compression regime. The resorcinol-formaldehyde aerogels possessed a high specific surface area (200–510 m2/g) and porosity (41–82%), with a surface fractal dimension of 2.2–2.5. The mechanical strength of the materials reached high values (up to 31 MPa) and was well correlated with the density of aerogels (0.27–0.86 g/cm3). The results obtained demonstrate the dramatic influence of the nature of a solvent used during the gelation of resorcinol-formaldehyde aerogels on their structure and properties.