Santiaguito, an extrusive domal complex in southwestern Guatemala has recently exhibited renewed domal growth, as much as 50 meters vertically in the first twelve months of growth. Synchronous with this activity, near the other end of the complex 1.3 km distant, there are pyroclastic eruptions. Ninety percent of the extensive hot lumarolic emission at Santiaguito is concentrated near the active pyroclastic vent, although numerous other lumaroles are found including a group of particularly hot vents associated with the current dome extrusion. Description and tabulation of chemical and mineralogical characteristics of sublimates and condensed gas from fumaroles at eight localities on the mountain illustrate the essential similarity and also the minor differences. The differences are in many instances related to volume of gas, the amount of rainwater dilution, and amount of oxidation of the gases along their path.