Introduction In complementary medicine, chronic, subclinical imbalance of acid-base regulation is considered a risk factor for chronic diseases. It is, however, unclear how this can be detected diagnostically.The objective was to study the reliability of an acid-base titration method according to Joergensen and van Limburg Stirum. Method The pH values before and after gradual titration using HCl was measured in two venous blood samples (day-1 and day-3) in healthy volunteers (n = 57). The blood test on day 3 was analysed twice. Results Data could was available from 48 subjects. Comparison of data from day 1 and day 3 showed a statistically significant difference in the blood pH before titration with average values of 7.45 (day 1) and 7.46 (day 3), respectively. Comparison of day 3/measurement 1 with day 3/measurement 2 showed no significant differences in the blood pH values. Conclusion The difference between days 1 and 3 is likely due to changes in setting factors which could not be controlled for. The blood titration method according to Joergensen and van Limburg Stirum seems to have an acceptable retest-reliability.