**R-DECO: An open-source Matlab based graphical user interface for the detection and correction of R-peaks** **Repository Description** 1. R_DECO.m: Opening code of the GUI 2. Common: Folder that contains general codes which can also be used outside the GUI 3. Examples: Folder that contains a Matlab and Excel example signal 4. R_peak_detection: Folder that contains the main algorithm and GUI codes **How To Open The GUI** Type R_DECO in the Matlab command line and press enter. The opening code will ensure that the necessary folders are added to the path and initialize the GUI. **License** See the Software License Agreement file for license rights and limitations. By downloading and/or installing this software and associated files on your system you agree to use the software under the terms and conditions as specified in the License agreement. **Citations** When using this toolbox for research purposes, please cite the original publication: Moeyersons J, Amoni M, Van Huffel S, Willems R, Varon C. 2019. R-DECO: an open-source Matlab based graphical user interface for the detection and correction of R-peaks. *PeerJ Computer Science* 5:e226 [https://doi.org/10.7717/peerj-cs.226] **Requirements** Matlab (Signal processing toolbox)