A potassium chloride-containing salt substitute lowers blood pressure levels, but its overall acceptability has been of concern due to its potential adverse effects on food taste. In a large-scale, blinded randomised trial evaluating the comparative effects of a salt substitute (65 % sodium chloride, 25 % potassium chloride and 10 % magnesium sulphate) and a normal salt (100 % sodium chloride) on blood pressure, we collected data on the saltiness, flavour and overall acceptability of food. We performed this at baseline, 1, 6 and 12 months post-randomisation using 100 mm visual analogue scales for assessments of both home-cooked foods and a standard salty soup. The mean age of the 608 participants from rural northern China was 60 years and 56 % of them were females. In the primary analyses, the changes in the saltiness, flavour and overall acceptability of both home-cooked foods and a standard salty soup were not different between the randomised groups (all P>0·08). In the secondary analyses, weighting each of the data points according to the lengths of the respective follow-up intervals, the flavour of both home-cooked foods (mean difference = − 1·8 mm, P = 0·045) and a standard salty soup (mean difference = − 1·9 mm, P = 0·03) was slightly weaker in the salt substitute group. We conclude that salt substitution is both an effective and an acceptable means of blood pressure control. Possible small differences in flavour did not importantly deter the use of the salt substitute in this study group, although the acceptability of the salt substitute by a more general population group would need to be confirmed.