Basic Mg-Al hydrotalcite, prepared by co-precipitation method, was calcined at 450 °C to form mixed oxides which were subsequently rehydrated to restore hydrotalcite structures with Brønsted active sites. The catalyst with these active sites was then studied in aldol condensation of acetone and furfural as a model reaction, in wide range of acetone to furfural molar ratio (2:1 – 10:1). Furfural conversion of 98 % was reached in 20 minutes of reaction time over rehydrated hydrotalcite, using a molar ratio of acetone to furfural 10:1. Catalyst characterization was performed by a combination of conventional analytical techniques, such as TGA-MS, XRD, N2 physisorption and DRIFT, the activity dependencies on the structural and chemical properties being discussed, based on the data obtained.