This chapter describes the in vivo delivery of conventional mRNA or alphaviral replicon RNA via intradermal electroporation. The use of RNA in clinical applications has several potential advantages compared to DNA. For instance, RNA cannot integrate into the host genome, and it does not contain bacterial sequence motifs such as CpG often present in plasmid DNA backbones that can potentially trigger autoimmune responses. Intradermal electroporation is well tolerated and causes only minor trauma compared to intramuscular electroporation. As the skin houses high concentrations of antigen-presenting cells, vaccines could especially benefit from intradermal administration of RNA.