The paper reflects upon the issue of human stress detection using Electrocardiogram (ECG) and Heart Rate Variability (HRV) signals. This includes pre-processing of ECG signal, HRV signal extraction, feature selection and their classification. Pre-processing includes removal of power line interference, baseline wanders etc. from the raw ECG. Pan-Tompkins algorithm is used for extraction HRV signal from ECG signal.The ECG is classified as stress or normal by setting the appropriate threshold value. Short term ECG needed for stress detection produces a reliable output of great accuracy.