A process and apparatus are disclosed for hydrocracking hydrocarbon feed in a hydrocracking unit and hydrotreating a diesel product from the hydrocracking unit in a hydrotreating unit. The hydrocracking unit and the hydrotreating unit share the same recycle gas compressor. A make-up hydrogen stream may also be compressed in the recycle gas compressor. A warm separator separates recycle gas and hydrocarbons from diesel in the hydrotreating effluent, so fraction of the diesel is relatively simple. The warm separator also keeps the diesel product separate from the more sulfurous diesel in the hydrocracking effluent, and still retains heat needed for fractionation of lighter components from the low sulfur diesel product.