Eddy-correlation measurements of particulate sulfur fluxes at the 1981 and 1982 Dry Deposition Intercomparison Experiments indicate a strong diurnal variation in deposition velocity (downward flux divided by concentration) at a height near 6 m. Values are considerably greater than suggested from wind-tunnel and theoretical investigations, but are similar to past results obtained by use of the same techniques over lush vegetation. Relatively small deposition velocities are found in neutral and stable atmospheric conditions or over surfaces that lack complex fine structure. The most likely source of possible invalidation of these results is interference by rapidly deposition, unknown, ambient, gaseous, sulfur compounds not removed by the present practice of using a denuder tube on the sample airstream leading to the sulfur sensors. (Copyright (c) 1985 by the American Geophysical Union.)