Abstract: Use of Clonazepam was very common in Parkinson’s patient with sleep problems such as rapid eye movement behavior Disorder. A pilot study was performed to evaluate the effects of Clonazepam on sleep pattern in Parkinson’s patient using video polysomnography. Overnight polysomnography was performed prospectively in three healthy males (age 51.33±3.51 years) and with three male Parkinson’s patient (age 60.00±8.00 years) with sleep disorders. The study was conducted in two phases using standard techniques in accordance with guidelines published by the American Academy of Sleep Medicine (AASM). For sleep stages evaluation, an electroencephalogram (4 channels with 2 central and 2 occipital) chin electromyogram (with 1 channel) and electro-oculogram (with 2 channels) were achieved. Polysomnography characteristics of healthy volunteers and Parkinson’s patient with and with out Clonazepam effect was evaluated. Sleep latency was compared between healthy volunteers and Parkinson’s patients in both the phases. The difference was highly significant [Phase I (p = 0.004, R2 = 0.896), Phase II (p<0.001, R2=0.999)], but there was no considerable effect of Clonazepam in PD Patients [Phase I, (p = 0.606, R2=0.072) Phase II (p = 0.726, R2 = 0.081)]. Clonazepam significantly increases the sleep efficiency [Phase I (p<0.001, R2 = 0.991) Phase II (p = 0.002, R2=0.998)] in Parkinson’s patients but Clonazepam did not have any significant effect on wake after sleep onset, stage I sleep, sleep latency and wakefulness. Hence a larger population based longitudinal study should be performed to validate these findings.