A tile-based graphics processing pipeline that uses primitive lists that can encompass plural rendering tiles includes a primitive list reading unit that reads primitive lists for a tile being rendered to determine primitives to be processed for the tile and a rasterizer that rasterizes input primitives to generate graphics fragments to be processed. The pipeline further comprises a comparison unit between the primitive list reading unit and the rasterizer that for primitives that have been read from primitive lists that include plural rendering tiles, compares the location of the primitive in the render target to the location of the tile being rendered, and then either sends the primitive onwards to the rasterizer if the comparison determines that the primitive could lie at least partially within the tile, or does not send the primitive to the rasterizer if the comparison determines that the primitive definitely does not lie within the tile.