L-dopa given to Parkinson's disease (PD) patients for prolonged periods or at sustained high doses is known to produce disabling choreiform and dystonic dyskinesias. The production of dystonic dyskinesias at small doses in patients with deep brain stimulation surgery (DBS) has been poorly reported. We present a case series of 13 patients who tolerated high doses of l-dopa prior to DBS, who subsequently developed severe disabling dystonic dyskinesias on minimal doses of l-dopa after surgery. Of the 13 patients (7 male, 6 female), mean age was 54 (range 46–63), and mean disease duration was 10 years (range 6–17). 11 patients had presented with tremor as their first motor symptom of PD, and 10 had developed dyskinesias prior to surgery. At time of DBS the mean calculated L-dopa equivalent dose was 1073 mg (range 480–1566.7 mg) of which the mean l-dopa dose was 581 mg (range 300–1350 mg). The mean time from DBS to develop dystonic dyskinesias was 3 years (range 0.3–5 years), at which time the mean l-dopa equivalent dose was 366 mg (range 50–660 mg) and the mean l-dopa dose was 196 mg (range 50–600). Replacing l-dopa with a dopamine agonist either removed or largely relieved this motor complication. This case series highlights an important motor complication in the DBS PD patient and suggests one method to ameliorate it. It also raises important questions about the mechanism for reduction of dyskinesia threshold following DBS.