Chromatographic methods have been essential tools for analysis and purification of synthetic oligonucleotides since the 1970s. Significant developments in terms of instruments and stationary phases (media) have been made during the past several decades; among the latest are sub-micron to micron particles for the media, as well as ultra performance liquid chromatography (UPLC). Micron and sub-micron particles have increased product resolution. Applications of recently developed methods such as IP-RP-HPLC and LC-MS have been discussed for analysis, along with use of various methods for purification. Utilization of UPLC has decreased analysis time, increasing the throughput for analysis. Commonly used methods for analysis and purification of synthetic oligonucleotides have been described in this unit.