Besides its function as an information carrier, RNA acts as a non cell-autonomous signal molecule that regulates gene expression and development in plants. To this end, various types of RNA molecules travel locally, from cell to cell, and systemically, throughout the entire plant. Here, two major types of RNA intercellular transport are summarized: local and systemic movement of genomic RNA of invading viruses, and cell-to-cell and long distance transport of cellular RNA, i.e., endogenous messenger (m)RNA and RNA elicitors of post transcriptional gene silencing. The viral and cellular proteins involved in these transport processes are described and possible molecular mechanisms of their action are discussed.