To define the relative contributions of various sources of respirable airborne dust on longwall faces, continuous dust level data were recorded on five longwalls for an average of five shifts each. Analyses of these data with records of face activity showed that it was possible to determine the overall contribution of each major element. Average levels were determined for roof support generated dust, conveyor and intake dust, and for dust levels during various shearer activities. When average levels were compared between mines, a significant degree of consistency was noted. To differentiate the various dust sources associated with the shearer, fly cuts ranging from 6 to 3o in were closely monitored, as were dust levels at operator positions over the various segments of the longwall cycle. These data indicate that the clearance ring of the shearer drum is a disproportionately heavy contributor to shearer dust make. A statistical analysis of the effect of shearer haulage speed on dust make revealed that high haulage speeds are associated with low specific dust make.