An oil-extended styrene-butadiene triblock copolymer (SBS) was compounded with different amounts of powdered anthracite (0 to 60 wt.-%) without addition of stabilizers, Injection molding test specimen were exposed to an artificial atmosphere in a Xenotest apparatus for 500 to 2000 h. The effect of filler loading on the mechanical properties of the compounds was examined both before and after the weathering experiments, The unfilled samples showed a dramatic loss of mechanical properties already after 500 h of exposure, whereas the properties of the filled samples remained almost unchanged up to an exposure time of > 1000 h, Furthermore, the resistance of the filled samples against weathering increased with increasing filler content.