Warm Mix Asphalt (WMA) is a technology that allows significant lowering of the production and paving temperature of the conventional Hot Mix Asphalt (HMA). This technology promises various benefits, e.g. lowering of the greenhouse gas emissions, reduction of energy consumption, improved working conditions, better workability and compaction, etc. However, in order to reach widespread implementation of this technology, it is necessary to prove that WMA has the same or better mechanical characteristics and long-term performance in comparison with HMA. This article presents a laboratory study that has been conducted to evaluate two different WMA technologies – chemical (using Rediset WMX) and organic (using Sasobit). The testing consisted of two parts – determination of changes in rheological properties of bitumen and testing of asphalt mixture. The properties of bitumen after modification with two different dosages of each WMA additive has been tested by traditional EN test methods and using the Dynamic Shear Rheometer (DSR). The results suggest that binder containing Sasobit at in-service temperatures has improved elasticity and lover viscosity than pure bitumen. Asphalt testing has been performed for the Stone Mastic Asphalt (SMA) mixture. At first, the necessary changes in testing conditions were determined for adequate comparison with reference HMA – it was established that two hour asphalt ageing is essential before preparing test specimens. Then, the mechanical properties of WMA were determined after compaction with two different methods - gyratory compactor and Marshall hammer – at four different compaction temperatures. The results of compactibility, density, stiffness modulus and resistance to permanent deformations show that it is possible to reduce the compaction temperature of 155oC for HMA to 125oC for both WMA products with maintaining similar mechanical characteristics as HMA.