A tile-based graphics processing system comprises a graphics processing pipeline comprising a plurality of processing stages, including at least a rasteriser that rasterises input primitives to generate graphics fragments to be processed, and a renderer that processes fragments generated by the rasteriser to generate rendered fragment data, and a tile buffer configured to store data locally to the graphics processing pipeline. The graphics processing system is operable to cause data for use when performing graphics processing operations for each tile of a set of plural tiles of a plurality of tiles to be loaded into the tile buffer before causing graphics processing operations to be performed for any of the tiles of the set of plural tiles.