Objective: The objective of this study was to clarify the relationship between autonomic and non-autonomic non-motor symptoms in patients with Parkinson’s disease (PD). Methods: Sixty-five PD patients were included in this study (27 men and 38 women; aged 68.5 ± 10.0; Hoehn and Yahr (HY) stage 2.6 ± 1.1). The autonomic symptoms were evaluated by the Japanese version of the Scales for outcomes in PD autonomic (SCOPA-AUT) questionnaire. The patients were assessed with the mini-mental state examination (MMSE), PD sleep evaluation scale-2 (PDSS-2), Epworth sleepiness scale (ESS) and Beck’s depression inventory II (BDI-II). The Non-Motor Symptom Scale (NMSS) total scores and subscores of non-autonomic non-motor symptom domains (sleep/fatigue, mood/cognition, perceptual problems/hallucination, and attention/memory) were evaluated. A dopamine transporter (DAT) scan, metaiodobenzylguanidine (MIBG) myocardial scintigraphy, and card type olfactory identification test (open essence [OE, Wako]) were performed. Results: The SCOPA-AUT total score was positively correlated with the disease duration, HY stage, levodopa equivalent dose, PDSS-2, ESS, BDI-II and non-autonomic NMSS and inversely correlated with the MMSE. The high-SCOPA-AUT group (≥9) had lower MMSE scores and higher PDSS-2, ESS, BDI-II and non-motor NMSS scores than the low-SCOPA-AUT group (< 9). The DAT scan, MIBG uptake and OE score did not differ between the groups. In a stepwise linear regression analysis, which excluded possibly overlapping items among the scales, the subtotals of PDSS-2 items, except for item 8 (nocturia), (p < 0.0001) and non-autonomic NMSS domains (p = 0.00040) were significant predictors of the total SCOPA-AUT score. Conclusion: Our study shows significant correlations among autonomic symptoms, PD-related sleep problems and non-autonomic non-motor symptoms in PD patients.