New therapies are needed to improve current results in diffuse intrinsic pontine glioma. We present here the initial experience of administering Celyvir, autologous mesenchymal stem cells infected with ICOVIR-5, an oncolytic adenovirus that selectively replicates in cancer cells, by means of superselective intra-arterial delivery, in a patient diagnosed of diffuse intrinsic pontine glioma. Feasibility, safety, and morbidity rates of the superselective catheterization technique are comparable with those of diagnostic angiography. The intra-arterial approach warrants a greater contact of the mesenchymal stem cells with the tumor mass, and minimizes hemorrhages or vascular disruption. The tolerance to the 2 administrations was excellent, with no acute or delayed adverse effect, underscoring the feasibility of this technique for the delivery of virotherapies and/or cellular therapies in this location.