Background: Sedentary lifestyle is associated with low heart rate variability (HRV). Deep Relaxation Technique (DRT) increase HRV which reduces the risk of coronary heart diseases. Objectives: To assess HRV after practicing DRT to find out it's effect on cardiac autonomic nerve function in sedentary subjects. Methods: This cross sectional study was carried out in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University between July 2012 and June 2013 on 30 apparently healthy sedentary females aged 25-35 years (study) who were practicing DRT with 3 months duration. For comparison, age and BMI matched 30 apparently healthy sedentary females who had no experience of relaxation technique (control) were also studied. Both groups were selected from the sedentary housewives by personal contact. The study subjects were the participants in a private yoga center in Dhaka. HRV was assessed by a Polygraph. Statistical analysis was done by Independent Sample ttest. Results: Resting mean heart rate (p<0.001) was significantly lower and mean R-R interval and SDNN (p<0.001), RMSSD (p<0.05) were significantly higher in the relaxation group than the control group. Conclusion: DRT improves cardiac autonomic nerve function with parasympathetic dominance in sedentary females.