In this study the addition of calcium carbonate as filler in PLA matrix was investigated. Two kinds of calcium carbonate were used: Socal (S) and Solvay (U). Samples were prepared by melt mixing in Brabender plasticoder (share of filler 0.1, 0.5, 1 and 5 wt. %) and in solution mixing (0.1 and 1 wt. %). Mechanical and thermal properties were investigated using dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, universal testing machine as well as surface properties by measuring contact angle with goniometer. The results showed increased performance with the addition of calcium carbonate as filler in a polymeric matrix. DMA analysis results gave an insight into the primary viscoelastic material functions. Storage modules obtained are higher in the composite compared to pure polylactide indicating a greater ability of materials to withstand the load. The temperatures and enthalpy of phase transitions: glass transition, crystallization and melting obtained by DSC analysis show shifts towards higher temperatures. TGA analysis showed that the addition of filler improves the thermal stability of the materials, whereat the best results showed both composites containing 0.1 wt. % filler. Also, mechanical properties have been significantly improved for all shares of fillers. The results obtained on goniometer didn't give any clear conclusion on influence of added fillers on contact angle of composite and test liquids (water, formamide and diiodomethane).