The results of the treatment with L-Dopa of 33 patients (19 males and 14 females) are reported. The cases were separated, acording to their symptoms and signs, in slight, moderate, intense and severe ones. Age of the patients: between 42 and 78 years old. L-Dopa was administered in an initial dosis of 500 mg, associated to a MAO inhibitor; the dosis was increased 500 mg every 3 or 4 days, according to the patient's tolerance. There was a better improvement on all the phenomena dependent directly or indirectly of the rigidity, as related to the tremor. During the treatment the blood values of uric acid and urea had a tendency to increase; alkalin reserve had a tendency for lowering; the leucocyte count revealed an eosiniphilia which was sometimes very high. Collateral effects (adrenergic and dopaminergic) were analysed. The adernergic effects occured when L-Dopa was used associated to a MAO inhibitor and were represented by headache, paroxysmal arterial hypertension, facial rubor, profuse sweating, vesical tenesmus and angina pectoris. The dopaminergic effects, proportional to the clinical gravity of the case, were: arterial hypotension, coldsweating, cardiac arrytmia and lipothimia. Other complications were: anorexia, decrease of bowel movements, nausea, vomiting, psychic alterations with depression and euphoria. Among the neurologic complications are emphasized discinesias and acatisia.