The review encompasses ash characterization data from 16 different hazardous waste incinerators, both pilot- and full-scale, treating a variety of waste streams. Its focus is on 14 volatile organic compounds, 18 semivolatile organics, and 13 metals for which analyses were most frequently performed. Included are results of analyses of ash leachate prepared according to EPA's Toxicity Characteristic Leaching Procedure (TCLP). The most frequently detected metals in the ash analyses (as indicated by the fraction of analyses that were above detection limits) were chromium, zinc, copper, nickel, lead, arsenic, and silver. The most frequently detected volatile organic compounds were toluene, xylene, trichloroethene, acetone, methylene chloride, and 1,1,1-trichloroethene. Predominant semi-volatile organics were bis (2-ethyl hexyl) phthalate, naphthalene, phenol, di-n-butyl phthalate and pyrene. Metals were generally detected with greater frequency than organic compounds.