In the summer of 1918 he became ill and on 8 September was forced to go to Vienna for medical treatment, leaving the command of the army to the deputy commander-in-chief general Georgi Todorov. It was during this critical time when an Entente offensive in Macedonia managed to break the Bulgarian lines at Dobro Pole and lead to the capitulation of Bulgaria. On 4 November 1918 lieutenant general Nikola Zhekov was discharged from the active army and went into the reserve.