Duplex stainless steelsalso called austenitic-ferritic stainless steels, owe their name to the mixed austenite and ferrite structure at room temperature. Basis of duplex stainless steels is Fe-Cr-Ni-N system, whereas austenite (γ) and ferrite (α) are main phases. Main adventage of duplex stainless steel is very good corrosion resistance. They usually contain higher content of chromium, lower content of nickel and often contain molybdenum to increase corrosion resistance. In this paper microstructure analysis and microhardness testing was carried out on welded duplex stainless steel X2CrNiMoN22-5-3. Samples were welded so that the root of weld was welded with TIG process, and for filling REL process was used. Analysis of microstructure and microhardness was conducted before and after annealing (850 °C/ 60 min/ air). Afterannealing,the samples were metallographically prepared. Optical microscopy and scanning electron microscopy with energy dispersion spectrometer were used for microstructural charaterization. Before annealing microstructure was consisted of ferrite and austenite, and after annealing presence of sigma phase was determined in melting zone.Microhardness of samples before and after heat treatment was measured by Vickers method. After annealing it is noticed the highest increase in microhardness in melting zone (from 294,9 HV1 to 357,0 HV1).