Relaxation or meditation is expected to slow the heart rate and produce more stable rate changes. However, there is little information on specific effects of meditation training. In this study we compared heart rate stability during normal and meditation conditions. ECGs were recorded with ethical permission from normal subjects while seated, over 30-minute periods. The first set of control recordings were made with no instruction other than to remain still without talking. The subjects were then given instruction on relaxation and meditation techniques before a second similar 30-minute study period. These two recordings were made on separate days. Twelve subjects were enroled with a mean age of 36 years. Subjects of these ages were more likely to experience heart rate changes than older subjects The mean RR interval across all subjects during the first control recordings was 866±150 ms (mean±SD) and during relaxation and meditation 848±136, with no significant difference. In spite of no difference in mean RR interval, the RR variability (average subject SD) during meditation actually increased from 53±18 ms to 65±24 ms (p<0.05). In addition, it can be noted that when examining the beat-to beat changes, the SD of beat-to-beat RR interval changes was greater than that for the original RR distribution for both the control recordings and meditation recordings (both p<0.001). This effect was more pronounced during meditation. The expected effect of lower heart rates and lower heart rate variability during meditation did not occur, probably due to the slower and deeper breathing during meditation inducing greater changes.