The work reported in this paper correlates microstructure development after low temperature embrittlement heat treatments with pitting corrosion susceptibility in grade 2205 duplex stainless steel. Heat-treatments at 475°C for up to 255 hours were carried out and microstructures characterised using scanning electron microscopy (SEM) and micro-hardness testing. Local electrochemical measurements using an electrochemical micro-cell were carried out and the critical pitting temperature (cPT) determined. Short-duration heat treatments for up to 10 hours showed an increase in CPT, attributed to an improved electrochemical character of the ferrite. Long-term heat treatments (>50 hours) indicated a decrease in CPT due to the precipitation of other precipitates and the formation of elemental depletion zones.