Premixed and unpremixed hydrogen-based flames (air/H2, A/H2, O2/H2, and N2O/H2) and a premixed N2O/C2H2 flame produced using a total consumption nebulizer-burner were used as atomizers for several elements measured using atomic fluorescence spectrometry. The premixed flames were produced by mixing the fuel and oxidant prior to introduction into the fuel and oxidant ports of the burners. The unpremixed flames were produced by the mixing of the fuel and the oxidant beyond the burner orifice. The premixed flames were considerably more laminar and of higher temperature than the corresponding unpremixed flames. The premixed and the unpremixed N2O/H2 flames seem to be the most generally useful hydrogen based flames for atomic fluorescence spectrometric studies of most elements. (The N2O/H2 flames have a very uniform temperature over a large part of the flame and a relatively low flame background and noise.) However, if serious chemical interferences are present—e.g., silicate—then the N2O/C2H2 flame should be used. © 1969, American Chemical Society. All rights reserved.