The 3D printing technology has attracted a lot of attention over the last few years. One of the most important benefits (advantages) of 3D printing is that with this method very complex items could be produced relatively cheap in comparison with standard methods. One of methods of 3D printing is selective laser sintering (SLS). In SLS technique a whole spectrum of polymers materials can be used among which is polyamide 12 (PA12) or widely known as Nylon 12. In this paper samples of PA12 and nanocomposites PA12/TiO2 were prepared by mixing of PA12 powder with different amount, φ = 0,5; 1; 1,5; i 3 % of TiO2 nanofiller and further on direct pressing on hydraulic press and with mixing PA12 with TiO2 nanofiller in melt in Brabender plasticorder. The free surface energy of the components was studied by the contact angle measurement and adhesion parameters of PA12/TiO2 nanocomposites depending upon preparation method were determined. Thermal properties of sample were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The mechanical properties were determined by a tensile test. Results showed that preparation method of PA12/TiO2 nanocomposites has no significant effect on glass transition temperature, crystallization and melting. Influence of the nanocomposite preparation method is visible in crystallization (∆Hc) and melting (∆Hm) enthalpies. PA12/TiO2 nanocomposites prepared with direct pressing of PA12 powder and TiO2 nanofiller increased ∆Hc and ∆Hm which indicates that TiO2 nanofiller has nucleating effect on PA12 matrix. Thermal analysis showed that method of preparation and addition of TiO2 filler has no influence on thermal properties of PA12 matrix. Mechanical properties have not been significantly influenced by the preparation method of the PA12/TiO2 nanocomposites.