AbstractIt has been found that V+5can be potentiometrically estimated by titrating it with W+5or U+4. The process is applicable to small quantities of vanadium as low as 30 γ the titration curves are smooth with sharp inflections. The most favourable results are obtained with W+5in the presence of 7‐8NHCl and 0.1‐8NH3PO4, both at room temperature and at 60°C. With U+4the best results are obtained in