In the present study, we describe six patients who received autologous mesenchymal stem cell (MSC) therapy for symptomatic carpometacarpal (CMC) joint and hand osteoarthritis (OA). Six patients who received injections of adult autologous culture expanded MSCs in their thumb CMC joints were followed for 1 year posttreatment, and matched with four procedure candidates who remained untreated. We observed positive outcomes in the treatment group for both symptoms and function related to the OA, compared with a reported worsening among the untreated controls. While these results should be interpreted with caution because of the small number of treated subjects and lack of placebo control and randomization, we find sufficient evidence for further investigation of MSC therapy as an alternative to more invasive surgery in patients with OA of the hand.