The purpose of this study was to investigate the potential relationship between the salivary electrical resistance, as measured by the Cue Fertility Monitor, and the time of ovulation. Twenty-seven cycles in 18 volunteers were analyzed. A slight correlation could be demonstrated between the day of salivary electrical resistance peak and the day of luteinizing hormone (LH) peak. However, the changes in salivary electrical resistance values, arranged to the day of LH peak, were not statistically significant. The days of salivary electrical resistance peak in relation to the day of LH peak were not reproducible in individual women. The apparent relationship between the day of salivary electrical resistance peak and the day LH peak might be explained by the methodology used. It is concluded that measuring the salivary electrical resistance is of no use in predicting the day of ovulation.