Duplex and superduplex stainless steels are corrosion resistant alloys with many uses in chemical and petrochemical industries. It is generally accepted that these alloys present stress corrosion resistance superior to austenitic grades, but it does not mean that they are immune to this type of failure. Under severe conditions of temperature, stress, low pH, high chloride and H 2 S contents superduplex steels may fail environmentally assisted cracking (EAC). In this work, superduplex UNS S32750 steel specimens were subjected to critical environmental conditions which produced stress corrosion cracks. In the first experiment the material was tested by slow strain rate tensile tests at 80°C in a solution with 115,000ppm of chloride, H 2 S partial pressure of 6.75psia, and pH=3.0. In a second experiment the material was subjected to four bend beam test in a solution similar to experiment 1, but with a H 2 S partial pressure of 30.0psia. Finally, a third test was conducted in a bend plate of superduplex steel subjected to MgCl 2 saturated solution at 154°C. The cracks produced in the three experiments showed quite different features, which were investigated by optical and scanning electron microscopy.