A method and system for coding mode selection using estimated coding costs. To provide high compression efficiency, for example, an encoding device may attempt to select a coding mode for coding blocks of pixels that codes the data of the blocks with high efficiency. To this end, the encoding device may perform coding mode selection based on estimates of coding cost for at least a portion of the possible modes. The encoding device may estimate the coding cost for the different modes without actually coding the blocks. In fact, in some aspects, the encoding module device may estimate the coding cost for the modes without quantizing the data of the block for each mode. In this manner, the coding cost estimation techniques may reduce the amount of computationally intensive calculations needed to perform effective mode selection.