Current therapies do not induce significant benefits in chronic stroke patients. Preclinical studies suggest that autologous transplantation of adipose tissue stem cells may be of benefit. This phase one clinical trial was developed to test the safety and efficacy of adipose tissue mesenchymal stem transplantation in chronic stroke patients. Three patients received stereotactic infusion of these cells. The first objective of the transplantation was to evaluate the safety profile with a follow-up of six months. The second objective was to detect any improvement in neurological function. Changes in brain parenchyma were monitored by MRI. All three patients showed significant improvements at six months after treatment (assessing the change from the pre-transplant baseline in dedicated indices such as the National Institutes of Health Stroke Scale and the Berg Balance Scale). During the six-month observation period, no transplant safety issues were observed. A change in signal conduction (detected by MRI) was observed in the infusion area, which, as indicated by the authors, could be correlated with improvement in neurological symptoms.