INTRODUCTION: The purpose of this trial was to evaluate preliminary efficacy and safety of multiple intravenous infusions of autologous, Hope Biosciences adipose-derived mesenchymal stem cells (HB-adMSCs) for the treatment of patients with Parkinson's disease (PD). METHODS: A total of N = 24 patients with PD were randomized 5:3 into HB-adMSC (200 million) or Placebo. Six intravenous infusions of HB-adMSCs or saline were administered at Weeks 0, 4, 8, 16, 24, and 32 with a follow-up at Week 42 and the end of study (EOS) at Week 52. The primary efficacy endpoint was to investigate change from baseline to Week 52 in Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part II. Primary safety endpoints included the incidence of adverse and serious adverse events (AE/SAEs) and clinically significant changes in laboratory assessments. RESULTS: HB-adMSC treatment was well tolerated and safe, with only one SAE reported, which was deemed unrelated to the investigational product. In total, 81 AEs were recorded, 79 of which were mild, one moderate, and one severe. Neurological disorders were the most commonly reported AEs, with a higher incidence in the placebo group (66.7%) compared with the HB-adMSC group (46.7%). No deaths occurred, and no clinically meaningful changes were observed in laboratory parameters from baseline to the EOS for either group. Efficacy analyses revealed no clear treatment effect in MDS-UPDRS II scores between the HB-adMSC and Placebo groups. CONCLUSION: Multiple intravenous infusions of autologous HB-adMSCs were found to be safe and feasible in the patients with PD. Efficacy outcomes should be interpreted with caution, as this small, early-phase study was not designed or powered to demonstrate definitive efficacy. Trial Registration: ClinicalTrials.gov identifier: NCT04928287.