Tardive syndromes (TDS) typically manifest 3 months or later after exposure to antipsychotic drugs, and unfortunately have no satisfactory medical treatment. We explored the possibility of using therapeutic repetitive transcranial magnetic stimulation (rTMS). Twenty-six patients were allocated to receive real or sham rTMS over the hand/arm area of motor cortex (M1). Each received a daily total of 2000 rTMS pulses (20 Hz at 100% rMT: 1000 stimuli per hemisphere) for 10 consecutive days. Outcome was assessed using the Abnormal Involuntary Movement Scale (AIMS) and TMS measures of M1 excitability. Three patients in the sham group failed to complete the study. At baseline, there was no significant difference between the groups in age, sex distribution, duration of illness, AIMS score and drug treatment. rTMS improved symptoms in both groups. However, there was a greater reduction in the AIMS score of the real rTMS group compared with the sham group (real, 8.3 ± 1.7 points; sham 1.2 ± 3.3; repeated measure analysis ANOVA Time X Group interaction P = 0.001). The same trends were observed in the clinical subscales. Following treatment, MEP amplitudes at higher intensities (140, and 150%) increased more in the real treatment group than in the sham group. This is the first clinical trial study of bilateral hemispheric rTMS in patients with TDS and suggests that 20 Hz rTMS might be a feasible treatment option in patients unresponsive to "first-line" treatment. Clinical trial registration ClinicalTrials.gov Identifier: NCT03145311.