Multiphoton spectroscopy of monodeuterated water is employed to determine more than 210 new energy levels of HDO in the 25 000–35 000 cm region. These new empirical energy levels are used to fit a potential energy surface (PES) valid between 20 000 cm and 35 000 cm. Using this PES and an accurate lower energy PES as starting points, an energy-switching surface is constructed which is capable of reproducing the whole HDO spectrum from 0 to 35 000 cm. This PES is used to calculate a line list for HDO which covers infra red, visible and near ultraviolet transitions.