In this paper the effect of ultrasound and electrocoagulation on the removal of manganese from synthetic wastewater was investigated. It was shown that 20 kHz ultrasound alone is not very efficient for manganese removal, but it enhances the efficiency of electrocoagulation. It was also shown that settling has a great effect on the electrocoagulation process because it stabilizes the flocs. A total of four laboratory-scale experiments were conducted, and the optimal experiment included 10 minutes of ultrasound and 10 minutes of electrocoagulation with iron electrodes. Under these conditions, 89.0 % of the manganese was removed with an operating cost of 0.13 EUR/mg Mn. Adding the cost of replacing the immersed ultrasonic probe, the total operating cost increased 3000-fold, making the immersed ultrasonic probe method unviable for large-scale application.