Following novelties in the construction industry, the use of construction and demolition waste or other recycled materials such as tire, glass, straw etc. is increasingly frequent and requires verification of all physical and mechanical properties of such materials and definition of their usage and final application. In this work we have tested and described the waterproofing of concrete mixtures with recycled aggregates. Waterproofness can be achieved by adding certain chemical additives to concrete or using sealing strips in the joints of two concrete surfaces. For the experimental part of the work five concrete mixtures were made, four of them with recycled materials and one reference mix with natural aggregate, ie. dolomite. Experimental testing of concrete mixtures in fresh and hardened state, and testing of water penetration, were made in accordance with Croatian standards. Based on the results obtained by experimental investigation, properties of mixtures and their behaviour were analysed with respect to the waterproofing of concrete with recycled aggregates.