REM sleep without atonia (RSWA) is a key feature of REM sleep behavior disorder (RBD). However, detailed visual scoring of EMG on 30 and 3s intervals is highly time demanding. A computer program with automated scoring algorithm would thus be a valuable asset for sleep professionals scoring RBD.Criteria’s for tonic (2xRMS baseline for >15s per 30s epoch), phasic (max amplitude >4×RMS baseline (or 2×Tonic), 3s epochs) and any (tonic and/or phasic) chin EMG activity were implemented in a software algorithm. Sleep stages, respiratory-, arousal- and artifact events were visually scored and imported into the software. Visual scoring of EMG activity done by a blinded board-certified sleep professional was compared to the software algorithm by regression analysis and Kappa statistics. A total of 31989 3s epochs in 19 patients with Parkinson’s disease (PD) were evaluated (mean age 65.2±9.7, 10 RBD+, 9 RBD−).Total percentages of tonic, phasic and any muscle activity correlated strongly between the software algorithm and visual scoring (R2>0.97 for all activities). Cohen’s Kappa indicated very high agreement on individual events (0.73 for tonic, 0.80 for phasic, 0.83 for any activity). A cut-off value of 10% of any activity separated both groups correctly. Bouts of phasic activity were longer in patients with RBD compared non-RBD (375.4±61.1 versus 478.3±88.9, p=0.014).Our software reliably detects altered chin muscle activity in PD patients when excluding artifact corrupted epochs, providing a fast tool for detecting RBD patients and metrics for correlation analysis with clinical variables.