In the present study, we investigated temporal preparation in Parkison’s disease patients during a variable foreperiod before the appearance of a visual target. Patients suffered either of the idiopathic (referred to as ‘iPD’) or of a rare genetic variant of the disease (referred to as ‘Parkin’). In controls and in all patients temporal preparation induced decreased saccadic latencies, showing an oculomotor instantiation of the variable foreperiod effect. However, in controls and Parkin patients, the latency of saccades was also influenced by the duration of the previously experienced foreperiod. On average, this temporal short-term memory effect was not observed in iPD patients, either ON or OFF L-Dopa therapy. We suggest that the influence of the hazard rate on temporal preparation is not affected in PD and is not dopaminergic-dependent. However, the absence of a contribution of short-term temporal memory in iPD patients clearly shows the dual origin temporal preparation.