Objective: Dopaminergic treatment is proved to ameliorate motor deficits in Parkinson's disease (PD); however, it could have negative effects on behavior and cognition, including impulse controlling and decision-making. We aimed (1) to investigate the decision-making and impulse-control disorders (ICDs) of PD patients and their correlations with sociodemographical and clinical variables, dopaminergic treatment in particular, and (2) to determine the relation of decision-making with ICDs. Methods: The sample of 39 patients with PD and 37 healthy controls underwent cognitive tests and the task which analyzed decision-making (Iowa Gambling Task [IGT]). Besides assessing motor and nonmotor symptoms of patients with PD, ICDs were also scanned using the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease. Results: Although patients with PD performed similarly to healthy controls on IGT, decision-making profile in PD related to clinical variables: dopaminergic treatment and duration of illness. In addition to this younger age of onset, higher dose of dopamine agonists, longer duration of illness, and impaired decision-making were together accounted for a substantial amount of variance in impulsive behaviors. Conclusions: Dopaminergic medication likely contributes to the impairment in decision-making, which may be the underlying mechanism of ICDs. Further studies will be necessary to understand the potential implications of this finding.