Constant immersion testing and slow strain rate testing (SSRT) are conducted on WE43 wrought magnesium alloy in a 3.5 wt.% NaCl solution. After solution annealing at 525°C for 8 h, the alloy was isothermally aged at 210°C for 15 h, 48 h, and 144 h to obtain under-aged (UA), peak-aged (PA), and over-aged (OA) microstructures, respectively. The solution annealed (SA) microstructure had the lowest weight loss ( 0.10 mg.cm-2 day-1) and UA microstructure the highest weight loss ( 0.20 mg.cm-2 day-1) corrosion rates after 32 days of exposure in chloride solution. A Y = kt⅟2 type relationship was observed for WE43 microstructures, where Y is the corrosion rate parameter, t is the duration of exposure in days and k is a rate constant. SSRT was carried out at an initial strain rate of 10-6 s-1 in air and 3.5 wt.% NaCl solution to investigate stress corrosion cracking (SCC) susceptibility. SCC susceptibility index was in the order PA > UA > SA > OA. Intergranular failure morphology on the fractured surface after SSRT in chloride solution can be attributed to micro-galvanic activity between grain boundary second phase and adjacent regions. Comparison of electrochemical measurements in unstressed and stressed conditions indicated two orders of magnitude difference in electrochemical resistance of the alloy. © 2018 University of Manchester and the authors.