The purpose of this study was to determine the reliability and validity of measuring resting radial pulse rates by the use of three measuring times: 15, 30 and 60 s; and two counting methods: one beginning with zero (0) and the other with one (1). A two-factor within-subjects experimental design was used to determine the mean difference between pulse rates obtained from the radial artery, and the heart rates recorded by simultaneous electrocardiographic (ECG) recordings. The sample comprised 206 students. Mean difference was used to calculate the extent of any differences between radial pulse rates and the rate shown by the ECG. The interaction between measuring time and counting methods was confirmed using a two-factor within-subjects analysis of variance. For all types of measuring time, the counting from zero method produced a greater mean difference than the counting from one method. For all measuring times, the mean difference between radial pulse rates and rates shown by the ECG were non-significant in the counting from one method. In other words, when the pulse rate is counted from one, the rates obtained at 15 or 30 s could be used to predict the one-minute resting pulse rates. The results of this study can contribute to the evidence base for this commonly used aspect of patient care.