Publisher Summary This chapter discusses the capillary supercritical fluid chromatography (SFC). SFC, a separation method undergoing considerable renaissance lately, has its origins in a pioneering experimental study on metal porphyrins. Increased column performance and speed of analysis in SFC originate in the mobile-phase properties. The mobile-phase viscosity and the solute diffusivity in the mobile phase are two most important quantities which determine the overall chromatographic performance. Their values in SFC are intermediate between those encountered in gases and liquids. Consequently, with the favorable mass transfer properties of SFC, higher efficiencies can be obtained in shorter analysis times than can be achieved through liquid chromatography in open tubular columns under "reasonable" instrumental conditions. Capillary SFC shares many instrumental features with micro-column liquid chromatography in terms of sampling units, detectors, and mobile-phase flow-rates.