Stroke is a leading cause of death and disability worldwide. Stem cell therapy is an emerging therapeutic modality with evidence of significant benefits in preclinical stroke models. A number of phase I and II clinical trials have now been completed, with several more currently under way. Translation to the bedside, however, remains a long way off, and there are many questions that remain unanswered. This review will summarize the current evidence and ongoing clinical trials worldwide, and explore the challenges to making this a realistic treatment option for the future.