A metastable ZrO2-Al2O3 solid solution was successully synthesized by coprecipitation of hydroxides over the range 0 to 25 mol% Al2O3. Combined evidence from XRD and Raman spectroscopy shows the presence of two forms t' (c/a > 1) and t" (c/a = 1) of the ZrO2 tetragonal structure. Al-27 MAS NMR analysis shows the existence of the three sites AlO4, AlO5 and AlO6 in the whole range of the solid solution. Results of this study provide further insight into the nature of the metastable solid solution.